I don’t know anything about bisq i cant speak to it. I mean more platforms trading ftc is good, so asking them to support it is certainly not a bad idea.
I mentioned before there have been others that traded usd to ftc … coinmkt comes to mind. I actually used them as they were US based and dealt in USD. now gone, seems a blog is in its place and https://bittylicious.com/ used to but removed usd. (pretty sure it used to be there) but they never held enough in reserve to sell to fill my needs, also europe based when in the US is always a little awkward since they arent on USD. if you go way back btc-e actually had feathercoin on it. but they didnt do enough business in it so eventually they stopped., and then of course got busted for laundering bitcoins from criminal enterprise.
I personally dont worry about direct usd to ftc at this point … most exchanges that would offer it , i wouldn’t use. (we all have our favorites) I think it is a case of building usage in the coin will drive interest and that will get the exchanges on board on their own. Doing it the otherway around doesnt hurt but it tends to be like watering the field with no seeds. If btc-e showed us anything, being on a huge exchange doesnt mean huge interest.
personally, I am just waiting for the day coinbase picks up ftc. I think they would if it did enough business in it, but the for some odd reason feathercoin has never quite gotten the interest needed to become mainstream. it kinda did about 2.5 years ago but it died down and never really picked back up.