Why won't my Researchers advance further in sandbox mode?

Question

I started an unlimited game and I just wanted to build up my Techs like I did in the campaign. It started well enough until I realized that my researchers just weren't advancing. I gave them all they need, they were 100% satisfied but when I went to toggle their tax I noticed that even at lowest tax value it didn't say they would advance. My Ecos say that only euphoric citizen advance ... my Techs just don't).

I also have a weird proportion of 1,000 lab assistants and 4,000+ researchers ... and I shall stress this they are euphoric ... they just won't advance! What do they need to advance?

Answer 1

The Tech faction only has two tiers of citizen. However, it's worth fully upgrading them, as labs and academies both become more effective depending on how many people surround them, and are an invaluable source for upgrades which can either be used directly or sold for licenses.

Answer 2

Seems researchers is as high as they go. I haven't been able to make money off of them but I do need them for their technology