The idea is to counter https://wiki.factorio.com/Scrap_recycling_productivity_(research), this infinite research tends to eventually clog most Fulgora bases because recycling scrap produces more but recycling everything else still happens at the same speed as before and items start clogging behind the recyclers dealing with the sub-products of recycling scrap. I know this can also be prevented adding a ton of (network) circuits to control that it doesn't happen... still this is the only productivity research where this is likely to happen.
The point I'm trying to make is that all the other type of productivity research will never clog your whole base ever, maybe "Asteroid productivity" can but it's less likely and more easily fixable, but Scrap recycling productivity can easily do it once a few levels are researched.
It should affect everything except scrap recycling.
