I’ve been offered a frame with either 112-49-BB30, 112-52-BSA, 112-56-BSA bottom brackets.

All being equal, I prefer threaded, but is everything equal.

On this kind of bike, does it affect q-factor, or anything else?

Bear in mind narrow Q-factor is only of benefit if you ride with your feet ‘straight’ – not unknown for those with bigger feet / ride toe-out for heels to clip the chainstays. Those dimensions would seem to indicate that you’ll need to fit some form of adaptor anyway – i.e. a BB30 bearing/6806 is 42mm diameter and PF30 is 46mm. I would stick to BSA as it probably gives you more options – What crank are you wanting to use?

I currently have a BB30 crank off a Boardman CX Team, but was hoping to move to SRAM Force 1, or similar 1x.

BSA would be my choice.

My workswell supplied BB bearings lasted 3,200 miles in all conditions though so I wouldn’t rule out BB30 (although mine is BBright).

Also just bought a new BB30 frame and got these: https://www.ribblecycles.co.uk/ribble-road-press-fit-bb-cups/#pid=18324

Standard easy to reach MR2437 bearings in a proper alloy case 🙂

Looks like Sram Force 1 uses 24mm spindle, so I guess I’m not limiting my choices by sticking with BSA.

I’m assuming that the 112 BB reference means a 112mm-wide BB shell – what width is the BB shell on your Boardman? You can get longer crank spindles, provided you can detach it from the spider.