From my experience with the app, as long as the transfer is initiated before the hour, I think your good. However I could be wrong but I don’t think I am.
When I shield my coins, once it registers that a transaction is made, it starts to pend and wait for conformations. The timer limit seems to be no longer present once a transfer is registered, but then again, I’ve never had a transaction go over an hour.
As for providing liquidity, you can either pair it with an equal amount of PRV with the add function, or you can put it in the provide tab by itself which is what I would recommend.