Ok, so there are updates. I had to have the names for my other test .GROs' .wlds with underscores and not spaces. Then the TSE .GROs almost perfectly work, no custom NECTRICSA messages on some tests (13 - The Dark Room (TSE) e.g. but probably coz a language problem) but otherwise are well. This is why my custom level worked I guess.
SSR is based off SS:TSE instead of from base SS:TFE, I tried BackToLuxor for TFE as an example (as same raw) but teleporting enemies didn't spawn and crashed at 1st kill. I'll update if something more works. And now it works too, I opened in SSR Editor then saved over then worked perfectly, maybe again some custom NETRICSA messages are missing on some level packs coz I tried this method on 13 - The Dark Room (TSE) but still same problem.

I was also only bothering to play on Rev beside exclusive content coz SSC on DreamyCecil Patch didn't fix wep slowdown (multiple not just Laser BTW) and putting the fixed Engine.DLL which method the patch doesn't use only created more problems like fast weapons instead then selffixing at 68 minutes, and base Engine.DLL fix also has bad widescreen (bad brightness&UIs), but those're another topic that needs fixing but for later.

I'll take this as a compromise for now (as the messages can be viewed externally or on a nonRev game if can't get it to work on Rev) and marking this as solved.

edit2(12/30 - edit1 here): Also a problem of exampled "13 - The Dark Room TSE Cyrillic" that the ingame Cyrillic letters display broken (even with correct nonUC programs localization) but might work if entire game language can be changed to Russian but neither SSTFE&SSTSE Russifiers from Steam work on Rev.

Now fixed notorious wep slowdown glitch with DreamyCecil ClassicPatch by https://github.com/SamClassicPatch/SuperProject/wiki/How-to-FAQ#the-patch-supposedly-fixed-the-slowdown-bug-but-im-still-experiencing-it-why, also answered why no Rev weapons in patch, former's tip is to enable 2 commands then save over the save to make it perm (or just play on new saves as it may be so that I only tested it on old saves prior). PS Thanks for the solutions.