Sure. That's all the "Smart" UPSes are - battery backups with line conditioners built in. Line conditioners often have some surge protection as well, so you will have two layers of surge protection too. You may want to change the setting higher for when the battery backup trips and set it for manual reset rather than automatic. As when the output from the LC drops outside of it's output regulation range, then the power from the wall has already dropped much more and you'll want the BBU to kick in pronto. And you'll want it to stay on until you are sure the AC from the wall is stable again - no automatic switching back to AC.
. Since all of these details are handled by the SMART units, you might want to consider going with one of them instead.
.bh.