Tried on my end as well last night:
1. Funded the minimum 2K
2. Exchanged 10 USD (this is the minimum they allow)
3. Did 6 x buy trades of VLTA consecutively (~2.24 USD per piece), selling them along the way to minimise exposure
Now have to wait at least 30 calendar days for the 60 + 40 USD worth of AAPL shares to be credited, i.e. 1-Jul-22.
Coincidentally, I was changing some USD in IBKR a few hours apart, so exchange rate comparison as such:
Webull = 0.723789
IBKR = 0.727775
Not too good, but I guess worth it just for the 100 USD AAPL shares.
And Webull cited to have really high PFOF on stocks: