Wanted to provide a quick datapoint for a refi w/ LenderFi via backdoor application from the bogleheads refi megathread (Hi Chikid24! see you posting there all the time)
LTV~64% high conforming 30-year fixed @2.625% (from 3.5%). Applied 8/7, locked rate 8/13, signed closing docs w/ notary on 9/4, and loan funded today 9/11. Just over a month to close, even with a title report delay.
LenderFi was pretty good, but note that they don't provide frequent updates, so you'll have to email 'em to get a response. However, when you DO email them, I get a response in less than 24 hours, which I found very impressive even with the hurricane of apps they received which caused them to shutdown their main page in the first place.
I applied to owning and loancabin as well, but owning required lower LTVs to qualify for the advertised rate (at the time was 2.625% for high conforming) and loancabin was not competitive whatsoever.