This isn't really an "issue" outright, but... It's probably most suitable here.

Can anyone suggest some INI Tweaks to make my draw-distances a little better? I've got everything set to maximum distance in the Launcher, but I'm still getting issues where grass is visibly drawing as a I approach, and sometimes looking out across the landscape is a plane and boring, because it's not loaded much there...

Any suggestions would be great

Not really. The ugrids line is best left alone, which is the only thing I know of that will load cells that are farther away. People only change that for screenshots. You really don't want to change it on a character you care about either to see what it does. Use a test character or save that you will never load again if you want to see what happens, but your game will suffer if you keep the settings non stock.

You might look at some LOD mods that can make the transition less jarring. I don't know if anyone has made a mod that adds fog to the game to cloak things that are at a distance, that can help too.