They once refused to be audited and then we have a lot of complains and says that they run on fractional reserves. I'm not familiar with the audits that you have posted, but as far I can remember, they still have a existing case coming from the US government.
If i can remember, Bitfinex (first creator of USDT) claimed to have USD reserve for all the created tokens then suddenly cyber authorities discovered that the generated USDT is created from thin of air which even caused an inflationary supply. I don't remember how the case was solved while i remember how many platforms started lunching their own stable coins including USDT itself which actually developed in many versions through different networks.