Staying at the base and repairing while you're away probably isn't worth it. They'd basically have to just put the repairs on a timer and run a timer to see if it has finished before you return. And then if it didn't, they'd have to figure out what wasn't yet repaired when you return and what was repaired, which would be a waste of time, imo. Chunks aren't loaded when you're away, so it can't just actively repair while you are away.
However, having it repair while you're there is an option and probably isn't that difficult. Whether it is worth the time to code it is the question. But it could also work like the drone in Stranded: Alien Dawn, where it will not do repairs, but will bring the resources to do those repairs to each thing that needs repaired and highlight those. It would still require going around doing the repairs yourself, but you wouldn't have to worry about whether or not you have the resources in your inventory and you could easily see everything that needs repaired. Still, if it can also do the repairs, that would be nice. It would need to be a command you give it so that it will not try repairing during horde night and end up broken on the ground and where you can avoid turning that on if you are trying to save resources for other things.