I didnt use CYA last year because it was clogging up my filter which in turn would restrict flow and shut down my SWCG at low rpm (800-1000). I have an automatic safety cover that is always closed unless someone is in the pool or I'm cleaning it so I don't really need it.
But you do! Using chlorine without CYA can be very corrosive which could explain why your cell failed. Even indoor pools should have a small amount of CYA to prevent this.

But even with a cover, you sometimes remove it during the day don't you? FC will not last even a few hours without CYA so you risk not only algae but bacteria breakouts. Plus, given the pool is exposed to sunlight on occasion, CYA will allow you to reduce the output of the SWG so it will last that much longer. Also, CYA should not clog your filter, that must have been something else, probably algae from the lack of FC. If added to the pool correctly, a sock in front of the return, there should be no problem with CYA.

Honestly, I think the problem with the short SWG life has more to do with the way you are managing your pool.