Tie call in's to teching, problem solved.
Thats still call-in meta and you won't even be delayed to pump first batch, on the contrary, it'll hit the field faster thanks to CPs acquired by tech.
Putting a band aid on a broken leg won't fix it.
Fundamental problem is with call-in armor having no disadvantage over stock armor, there is no need for any decision making, because the decision is obvious, need for tech won't change that for anyone except Ost.
Call-in meta will be fixed, when stock units will have equal appeal to field them instead of punishing you with inferior force which often require exponentially more micro due to fragility and numbers.
You can't say "tie call-ins to tech" because it won't fix anything at all, it just makes 2nd call-in unit arrive 3-5 mins later then it normally would.
Imagine you have fresh oranges and bad oranges. People always go for fresh ones, even if you will put them in one bad and force people to buy bad ones together with fresh ones, people will just throw away bad ones and keep the fresh ones, nothing will change except neglect-able cost increase.