My only gripe with modules are the Tact switches (Buttons) that can sometimes be a bit fickle and an area that quite a few manufactureres could look for more solid components.
Overall though, I only have 1 module that I bought second hand that has developed a fault, it still works and has all functions but there is an intermittent fault in either the multi-colour LED or the Tact switch on my Erica Pico DSP.
I've something like 89 modules and have been 'collecting' / 'feeding my habit' since 2019 with very good longevity of modules.
Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.