If you are putting in new craftable items, you should use those which can be made all over the mojave wasteland and not just in some crappy dlc.

Mind elaborating a little bit?

Where in the regular Mojave will you find a cosmic knife? Lol. Kind of the point to add new items with new dlc's.

The HH dlc added quite a few items that you could find, just scarce amounts like components to flake bottle cap mines.

Like blood shield, Datura hide, black blood sausage. nightstalker squeezin', Cloud kiss poisons, THICK RED PASTE ( If you cant make this paste then a whole perk is wasted)

All of these are items that you should be able to craft and use throughout the game and not just in one location.
If you think using them for an hour or two is more than enough for you, so thats another thing.

All craftable items should be craftable throughout the game. Items like a cosmic knife is a different thing, but even then you should be able to build more cosmic knives, since you wont be able to repair them to 100% if you cant make more of them.