If a puck feeder sits with water and a puck in it, it may well clog up.

There are myriad reasons why I do not advocate puck feeders, the biggest is that it tempts you to keep using the pucks when it's bad for your pool.

My suggestion: Yank the feeder out and use the fittings for the SWG. Meanwhile, if you are worried about the SWG failing, buy a $10 floater with adjustable openings and use THAT if the SWG fails and you can't be there to add bleach.