Pool seems to just drink up bleach so fast

If you install and dial in a SWG well before you leave it won't be an issue.
I was gone for 18 straight days last summer (temps were 105+ at my house). I dropped my pH to 7.2 and upped the SWG percentage 10%. On return the pH was almost 8.0 and the FC a bit over top end of target. Neighbor stopped by once to empty the skimmer basket. Water was still gin clear.