Advent Loyalists:

The Loyalists techs were IMO pretty well implemented. They have a cohesive theme in what sort of play they promote and for the most part accomplish their purposes.  I'm only going to discuss technologies I have a complain with

Planet for a Planet & Assimilated Populace:  These two technologies have similar effects(if opposite in thier activation conditions).  By and large they're good.  My only complaint is that despite saying they improve your ships's weapons neither affects strikecraft as far as I can tell.  Which basically means carrier heavy fleets gleen absolutely no benefit from the two largest combat bonuses technologies of the advent loyalists.  This is especially a bummer in that with the amount of AoE damage flying around these days Carrier fleets would otherwise be very attractive being that the drone host is by a large margin the Advent's beefiest Frigate.  Ancient Rettribution also probably doesn't affect strikecraft, but I'm not completely sure.  That said, other then that, these abilities are both great.

Global Unity:   A lot of people were excited for this tech when it was dug up in the game files, but the current implementation reall stifles it's usefulness.  1 culture/sec isn't going to push back enemy culture, meaning it's chief usefulness is in ensuring all of your worlds fall under friendly culture(for improve allegiance & combat benefits) without having to build a ton of temples.  The problem is, it's so late in the research tree and more importantly has enough high cost prerequisites that by the time you can get it you already have friendly culture spread throughout your holdings.  This needs to be either available earlier in the tree or have a new effect.

Advent Rebels:

I think in general the Rebels need a bit more work done with their technologies. 

Protection of the Unity:  Feels a bit underwhelming for a T8 research subject.  I suspect the extra 2% shield mitigation the advent loyals get make about as much of a difference in survivability(this will likely give what? maybe 1 extra shield regen per second for most ships?). 

Recharge Shields: Between this, Repulsion, and Wail of the Sacrificed it feels like the Rebs are meant to turtle more then the loyals.  That said, the stage of the game a shield-repair structure would really be useful is early game, when the rebels are trying to survive to the point where they get their techs(pretty much all of their technologies require a ton of labs).  I'd like to see the ability to repair shields stay on repair bays in addition to temples of renewal(even if that is currently a bug) and have this technology moved to T2 or T3 military tree with repair bays as a prerequisite. 

Return of the Fallen & Reanimation:  While I'm not proposing any changes I want to ask: Do these even work? I've never noticed them activating, but then again the larger battles where activations may be common it would likely be easy to overlook a few units reviving.  

Cleanse and Renew: This technology is decent.  That said, one problem the advent rebels have IMO is the rate they can destroy planets.  Between TEC loyal novaliths, TEC rebel bombardment technologies & the extreme damage of the TRT, and advent loyalist culture & the ability to instantly take planets with their titan the Advent Rebels are being left in the proverbial dust in terms of the rate they can conquer planets late game.  This tech would be the obvious place to address these issues.  Maybe add a secondary effect- something like +25% bombing rate of fire for all capital ships & titans to this technology?  Would let Advent rebels bombard a bit faster lategame and let the Eradica live up to it's name(with a name like Eradica, it seems an obvious candidate for planet extermination)

Mass Communion:  Feels underwhelming.  I suppose the goal is supposed to be while the Advent loyals go for early cultural expansion, the advent rebels are better at culture-bombing from behind well-fortified worlds.  The problem is that getting to this technology is very expensive.  it takes quite a few temples to make up for the money spent researching this tech.  I could see a few ways of expanding the benefits of this tech: the 25% discount could be extended to starbase Evangelism Nodes or have this technology also reduce the logistics used up by temple of communion(perhaps from 4 logistics to 3?).  

All other techs seem fine to me.  It might be interesting if expulsion's tax or culture benefit were swapped out for population growth rate to synergize with wail of the forsaken, but such changes are in no way necessary.