Obviously, there are downsides. This mod no longer supports land skirmish in any kind (as Research Labs are space structures, you'll encounter CTD as soon as you try it). You won't be able to see entire wonderful world of land pirates, as I got rid of them. Hopefuly soon we'll get them back.
Word of note - research is still possible, Res. Labs are now upgraded Golan-III, buildable at space colony level 1, with only one instance per planet. Also as it's impossible to build heroes, I gave each side a handful of them; it's also supposed to help early expansion, now more difficult due to lack of mining facilities - and smaller general income.
The mod currently fully supports GFFA and GFFA Lite (all space-related heroes are there) and Core Worlds campaigns (6 heroes per side). Also supported are Inner and Outer Rim campaigns (land units discarded, but no additional heroes added so far), while TC and OSH aren't touched yet - they'll require some more work, as some planets only have land garrisons. I'll probably expand this mod further, as I want to add many units to TC for both factions.
Inslalation: just unpack all the files to Phoenix Risings' xml folder. Make sure to make backup of your files.