I’ve had a quick look at FIL’s BSO and told him to take it to the LBS (I’ve pre-warned them it maybe arriving) as I’ve got the feeling that I’d have a tantrum working on it.
A few years ago I also spent ages advising someone about mid level full suss MTB’s and Hardtails with the advice to start on a nicely spec’ed hardtail from the LBS (not to get a 29er as it was still earlyish days of them). So he went and got a 29er FS in a box from the internet.
After building it up for him and going riding with him I felt sorry for the bike. I explained umpteen times that with a triple ring up the front, big/big & small/small on the gears was very bad he just wouldn’t take it in.
Worst of all was gear changing uphill, no attempt at backing off EVER, crunch/graunch every change. I explained that you don’t change gear in a car with the foot hard on the accelerator so don’t do it on a bike. He didn’t listen. It arrived a few months later wanting a new mech, mech hanger and a new chain after he’d twisted a link through 90 degrees, you’ve guessed it, big ring on the front, big ring on the back! I replaced all the bits and got it running and I think it’s been corroding safely in a shed for the last 18months.