I was told a while back that the average time to push a repack in my area is 10 minutes. And that's about right if there's not a lot of guest traffic. But I don't do it the way corporate says I should; way back when this first started, I was told to work a repack entirely before moving to another one. Forget that; with a 5, I'm in the feminine care and first aid aisles mostly, but there's other stuff in there too. Which is why I'll sort all of the 5s out onto the u-boat at the same time. It happens often enough that I'll find one each of a product in 3 different repacks from the same truck, so I sort first then push.
And yes, I quickly check bar codes for items that have more than one location. Right now I have Olly vitamins in the home location, plus a side cap, plus on those white display fixtures on wheels. (In previous non-retail jobs, I had to do a lot of proofreading of numbers and spreadsheets, and maybe that helps me be faster with checking UPCs against the shelf label.) Plus a couple kinds are on a cough & cold end cap.
I check EXF for products where I have back stock, but not for every product on the truck every day. That would take forever. And I'll check EXF when I'm pushing my 1 for 1 batches if more comes out than what will fit. If I identify a problem with capacity or floor count, I'll fix it then, but I don't go looking for problems. That said, I've learned the hard way that it's a good idea to check capacity and floor count when I set a sales planner or do a revision because a lot of the new capacities are wrong and then a boat load gets pulled from the back - and a whole lot gets re-back stocked. If I don't have time to do it right then, I'll try to get it done during my next shift. Waiting too long just makes things worse.