Thanks for the suggestions!
The logi and costruction area upgrades should be easy enough to implement, but for the change in recipe cost, well, there are a lot more things to work around, because I can't simply "change" a recipe (much like anything else in the game tbh) once the game has started.
What we modders do to fiddle with the numbers on anything that the devs didn't think about themselves (like, for example, when i add charge pads to robports or simply increase their power output) is actually "swapping" each one of those entities with an upgraded version that was already prototyped (read: defined) as a new entity, because the game wants every single entity prototype to be declared before even loading itself!
This same reasoning goes for recipes (that are handled in a similar fashion), so i'd have to prototype a bunch of new recipes and, whenever a technology gets researched, scavenge everywhere a recipe could go and hot-swap the old recipe with the new.
And that means at the very least the player recipe book, all the assemblers, all the blueprinted assemblers (for both blueprints the player already has, and for any new blueprint that builds roboports!)
And that's without taking into consideration the fact that, even if I worked around all of this, doing so will mess up production lines that ppl may have for roboports, making them all of a sudden unserviceable...
Another solution would be to simply add new tiers of roboports (like the gray, blue and yellow assemblers), but tbh I really don't want to go down this path...
Anyway i'll think about it in the next few days, maybe i can come up with something :D
Thanks!