imho they are somewhat OP because they add so much productivity at higher levels (4 * lvl 30 is 120% produkctivity).
In order to get some community feedback on this i created a poll: https://www.strawpoll.me/17297927
IMHO, the poll is missing one important option ...
i just finished a map with your mod, taking my time and playing very slowly at first, taking hours and days to get up to level 30-40 of modules, but sooner or later the aliens would help me to level up just by attacking the walls of my factory, even without biter farms. then i did the whole endgame with insanely OP setups, eg having only 2 or 3 vanilla assemblers (with your modules) for doing purple and yellow science at 200++ spm, and my rocket was built akmost in a matter of minutes. also making more than two full blue belts of plates from less than one belt of ore, only needing 3 smelters to handle a lane of compressed blue belts, or crafting 2 or 3 final items (not intermediates) at a time (progress bar advancing faster than the normal production) by doing normal crafts is very OP.
thus is see the biggest problem not (at least not directly) in the amount of bonus, but that i get the bonus for everything, including final products and not only on the intermediate products (eg i made 3 or 4 rocket silos and got 6 or 7). thus i don't want to vote for any of the current options that all are for nerfing one or more abilities of the modules (speed, productivity, etc), but for a mod setting that disables productivity for final products (just like vanilla), either completely disabling the alien modules for those recipes, or (preferably) only disabling the productivity component of their bonus when applied to those recipes of final products.
i didn't experience higher levels than that or what happens when i actively would kill biters (eg in biter farms), but then maybe also more features might be OP, but very difficult to balance. in general, i enjoyed the mod a lot, having to adjust all the time for ratios that change over time.