Dont really care about that kind of spell. If you jump down a tower, what's supposed to happen? It would feel like cheating a little bit to me.
Then actor will land on such a critic as you, who not check details and don't think about improvements before scream about cheating and demand axe feature, if Slowfall is cheating then all magic is cheating as well, with shield spell we protect them self from incoming damage, with Cure spell we heal self from damage without of any potions, with fireball we can damage enemy from distance without bows, thats all unbelievable cheating take it also from game :rofl:
If you don't know Slowfall before has such formula
Slowfall M points for D seconds
and thats effect
Reduces the damage taken by the subject from falling by slowing the rate of descent, but because of flawed implementation there is no difference in 1 M or 100 M since from bug they work equally, but D works well so what will be if spell will wear off while actor still at large altitude?
The same thats other falling actors will do, they will suffer from failing damage from constant increasing downfall speed from large altitude.
So what can be done magnitude of Slowfall damage reduction can depend on magnitude of spell (if used scroll or potion) or on used magicka for charging spell before cast like in Dynamic magic so higher reduction of falling damage need large amounts of magicka so only powerfull mages with large reserves of magicka for pumping up spell magnitude can jump down tower and during falling cast spell and reduce incoming damage to amount of used magicka, since magicka is blood of mage his health and source of powers so in exchange of reduced damage to health (thats can be easy taken by warrior because of his large health investing) mage will suffer from devastated reserves of his magicka, what can be fatal as well if enemies around and need to cast something.
Another thing thats D seconds time under slow hovering down is it, such parameter can depend on level in alterations school, so all mages who not skilled in alteration can use Slowfall for reduce falling damage in cost of magicka and fast drop like stone to earth, but only skilled in Alteration can hover long enough time and actually slow fall and safely lend to earth or slowly like feather hover into some place, in such cases they are really can be easy prey for shooters and casters, take an critical shoot from sniper or be dispelled at deadly altitude is not good idea, since mage will or die as slow target or will be forced to charge high amounts of magicka to compensate falling damage what also can be dangerus for mage, I think in such cases Slowfall really balanced and there is no cheating?
And yes since all magic in Skyrim has additional effects and different ways to be casted it Such alteration spell can combine Feather, Burden, Waterwalk and even Levitation Spell Effects like in this concept of Alter Gravity spell
At Novice level its work like feather spell on self, as burden at enemy, as gravitation trap thats slowing enemy on ground and charge will allow Jump at two times higher then normal jump, when channeled spell allow Slowfall, as channeled spell can be interrupted by lucky strike of enemy or (battle mages can have special training for reducing such chances thats can be implemented with perk) or with spell like Burden or paralyze or can be cleansed with Dispel or when Magicka is not sufficient for work of spell, channeled spells use different amounts of Magicka when it not sufficient its downgrades to lower perk for example mage has 150 Magicka float use 50 for cast and 5 drain for each second when Magicka lowered under 50 float will be changed with slowfall, additional checks can be added like check of player Fatigue and level of Encumbrance when Over-encumbered for example can become Burdened but instead of levitation will only allow float.
At Apprentice level when Mage understood Alternation better, Magnitude of Feather will rise, Magnitude of Burden rise, gravitation trap thats maximum burden enemy he still can attack but cant move and sink in water, charge will allow Jump at three times higher then normal jump, Mage can walk on water and don't crumble ice during channeling, but receive damage from walking over magma or another dangerous substance.
At Journeyman level Magnitude of Feather will rise, Magnitude of Burden rise more, gravitation trap thats paralyze enemy, charge will allow jump four times higher then normal jump, channel will allow float like a Lich and strafe backward without penalty, floating not allow change altitude higher then one jump height or half of it, anything higher will slowly decrease with Slowfal to one jump height or half of it, but can float over dangerous environment like lava and pits don't trigger pressure plates or similar traps.
At Expert level Magnitude of Feather will rise, Magnitude of Burden rise more, gravitation trap thats thats additionally squash enemy at end of duration, charge will allow jump five times higher then normal jump, channel will allow Levitate with both hand if another hand was equipped with something else not with gravitation spell player lose ability to rise altitude and start slow fall if spell was removed from both hands player will fall fast as normally, levitation use much more Magicka then float or water walk for cast and can drain more for sustaining.
At Master level Magnitude of Feather will rise, Magnitude of Burden rise more, gravitation trap thats rise and fall enemy into air at end of duration, charge will allow jump six times higher then normal jump, channel will allow Levitate with one hand.
With skill levels in Alternations school power of Burden and Feather will rise automatically as base spell, while channeling, charge and traps can require additional perks and added by perks dynamically by scripts into base spell when spell casted, all previous spell effects staked in higher level spell so for example Apprentice can both slowfall and and waterwalk, such way will allow remove from casted spell effects in restricted areas or trigger zones so there can be places where such magic negated like Mournhold in Morrowind just with simple script or create enemies thats invulnerable for such effect but can be harmed by other effects from that spell.