The science enhancers huge +150% (and 1 module slot) can actually be matched by 7 legendary productivity modules (+25% per), or 5 modules and +50% base productivity. This means the cryoplant can outperform the enhancer, and the EM plant can match it, even in vanilla factorio. This problem is even worse if there are mods adding higher quality levels or higher tier modules.

A fun idea I had to fix this is adding more module slots with higher quality science machines. +1 per quality level (+2 on legendary) would result in 7 slots in a legendary enhancer, allowing you to easily keep up on productivity or even use other modules (that's a lot of quality :D ). I do not know of any other machines with this property, so it would make the enhancer even more unique and fun.