I Immediately wanna say sorry for uncertainly in my behave. I'm going through that all first time, and some things I wasn't able to see will happen.
Why I'm doing that now?
Though it is all separate topics like join (https://developer.blender.org/D7939#192862), resize (https://developer.blender.org/D7946), join test func (https://developer.blender.org/D7970 and https://developer.blender.org/D7949#193022), moving other func around, they related trough common functions. And because there are many small changes I've made in common functions, I simply can't keep track of all that in separate branches. That's partly why my code became messy.
Another reason: I haven't enough time to carry all small changes from one branch to another, that's why they are not up to date.
That patch is not perfect at all, even when I uploaded the patch I saw a bunch of issues, but they are just implications of moving funcs around that were used by others or something like that. What I mean is that there is a lot of work remaining, I just ain't have time until the middle of July.
So, now about the code.
If U haven't looked at what it's capable of, check out links above. Also, I will add inline comments below for additional information.
There is only one big update on join_test func, see: {F8608267}
If for some reason u can't apply that patch and u want to, u can just copy/past full folder: https://drive.google.com/drive/folders/1SYjL-vpg6UpCWaKlvMP1KbrHv7lgLMaO?usp=sharing. Though I'm not sure if it will do the trick
**I'm do not leaving it like that, I will return after a month, but for now, I can only answer your questions**
I'm posting it here so u can play around and show me all bugs u have noticed, your wishes and what u think is not good about that in general