Is a 34" ultrawide at 3440x1440p a good fit to drive mac mini or external MBP display?

Recently I've sold my gaming PC which leaves me with a budget for a Mac Mini or more likely some variant of M4 MBP (I still need to work on the go sometimes). I am now left with a 'gaming' OLED 34" ultrawide at 3440x1440p. The pixel pitch isn't ideal for text so I am thinking of selling that too and replacing it with 4k or or higher resolution.

My current (older) MBP has somewhat unusual resolution that dosen't really map to common monitor resolutions. Not a big deal as I will like want to have two separate displays when docked, but still curious if there's a 'natural' mapping/scaling that works well with 1440p or 4k or higher?

Are there any specific 34-40 screens on the market that have very high 'retina' resolutions?