Ive got a set of 355 and flows.
If you have problems getting a tyre to inflate (with a trackpump), then the bead on that tyre isn’t tight enough…it will come off the rim if you ride hard. Non tubeless specific beaded tyres are much easier to burp than UST ready/2bliss tyres.
Get the rims, but run a tyre that has a tubeless bead.