Well, there used to be 20 labs required, in sequence 1-4-8-13-20.
It also used to be pre-release, that once tier was unlocked, like V, you could scrap away all the labs., you could research all that the tier unlocked. Then there was a version, where labs were all planetary, space labs were only to increase research speed.
if you do pve, you can get unity points via research or passive skill upgrades on colonizer capship.
Vasari loyalist (Exodus) faction has the labs on ships and starbases, not the 'rebels'(Alliance) they still do have that planetary slot that adds 1 influence and 3 civ build slots, so Asteroid gets 8 instead of 5. Later on I think V tier, 6. That is a huge amount. Meaning, 11 slots instead of 5.
As TEC, youre not doing great with slots either if you want trade. And a specific green planet to make exotics production faster.
You need tier 10 planet to be able to build +2/4 size upgrade to a planet. Meaning, moons, asteroids are out.
Old SoaSE:R needed 16 labs total. Neither 40 or 50. There were technically 8 tiers, in this one you have 10, made into 5 groups of 2 stacks. I do think the 50 lbs in total is excessive. If they are made more expensive, say, reduce them to 40, though I can imagine 30 as well.
There was also a version, that counted total number of labs, low tier research was much faster sped up.
You need also space for propaganda.