I removed the changes to wheat and leaves, buttons now have bark sides, birch fences have a shifted texture to minimize black spots, petrified slabs are fixed, pressure plates are log slices, and saplings are normal sized by default, getting slightly larger when they try to grow.
Wheat changes are still there - asked a friend to get another opinion and they did not like either as I was kinda uncertain which way to go at this point, so yeah not gonna integrate that one.
Buttons look nicer that way. Birch fence is much better. The saplings are better and it makes more sense now - when I placed them before and saw them small I hadn't realized it was state-based at all, that's kinda useful if you're trying to figure out if something can//can't grow where you've put it.
Log pressure plates are a little more by-taste than buttons (which objectively are a bit silly in vanilla, one would never use multiple tiny bits of plank, lol). I do like them, but I wonder if people would be annoyed that they no longer blend in with planks or not. Torn whether bark edges are a good idea for the pressure plates, as it would look better that way in some cases but when placed directly on a log it probably would look nicer and more correct as-is.
The one thing that irks me about tweaking these things (button, now pressure plate) are that logs aren't in the recipes, but I don't think it's worth letting that kind of logic get in the way of nice aesthetics when it's that minor. If I were in control of the recipes I'd just make log buttons and log pressure plates be variants with their own recipes that make more at once but end up costing more since it's logs. Anyway I'm getting off on a tangent.
You could probably have a market of users for these tweaks if you package them individually so people can apply them one at a time to whatever pack.
Edit: Integrated the discussed changes into a 5.1 release, was easy enough to not include the wheat file.