Talk me out of (or into) a 2020 X3 M40i with 50k miles — $32k

Long-time lurker.Currently stuck in a GMC Terrain (yes, I know) and I'm ready to get back into something that's actually fun to drive. I've got a kid, so I need an SUV that still hauls a car seat and gear, but I want to enjoy the drive for once.

Found a 2020 X3 M40i at an independent dealer:
- ~50,000 miles
- $32k out the door (one owner, personal use)
- Clean CARFAX and clean AutoCheck (score of 94)
- No accidents, no damage, clean title, clean odometer
- Dealer-serviced its whole life, recent brakes + brake fluid

From everything I've read, the B58 is basically the golden engine

My questions for the hive mind:
1. Is 50k the sweet spot, or the "stuff starts breaking" zone on these? What should I budget for maintenance out of warranty?
2. It's just past BMW's 60k CPO cutoff on age but under it on miles — worth trying to get a dealer to CPO it or buy an extended warranty? Or overkill on a B58?
3. Anything specific I should have a PPI check on the M40i besides the usual (oil filter housing gasket, cooling system, valve cover, VANOS)?

I test drive it Saturday and I'm honestly pretty excited. Considered a Porsche Macan but talked myself into the B58 being the smarter long-term play (simpler turbo setup, way cheaper to run). Tell me if I'm making a mistake.