Support for original rtp

I'm just wondering, cause I've tried to configure tangerine plugin to do this, couldn't understand even how to with nfnl (aniseed v2) and I think I'm seeing the possibility better with hotpot, but haven't been able to implement it yet (sorry, a bit noob). Why is not possible just to compile to default rtp? aka .local/share/nvim/site/... Also, I would like to separate everything as in rtp standard way. My plugins added with or without plugin manager go into /pack, my configurations in /plugin and my shareable stuff that I need to be able to require in different places in /lua (/fnl in my config dir, /lua in rtp). Maybe it's easier than I've been able to see with hotpot (git gud noob) but if anyone can help me gittin gud I'd appreciate it :) I don't know, adding new dirs to rtp seems to me kinda dirty without trying this first. Nice plugin!!! and thanks in advance just for the time reading this :3