This is a tough one. I know you said you probably don't
need the extra oomph of a MBP, but consider, for the same price (in the refurb store):
+1.4GHz
Quad-Core Processor
+Bluetooth 5.0
+A bit better GPU (Iris Plus Graphics 645)
+Touch Bar (both Affinity Designer & Photo have Touch Bar support)
- Only 8GB RAM*
Geekbench:
MBP vs
Air
*You could wait for 16GB RAM/128GB HD to show up as well, for the same price I'd assume (I don't see any in the store currently).
[edit]: Aha. I see
chucker beat me to the Pro.