No, if you use an adjustable daisy chain you do not need a fifi hook. Then it is as easy as attaching the extended chain to your placement and adjusting it to the desired length. As adjustable daysies are made from one tape, there is anyway no attachement point to place a fifi hook.
One sidenote: Extending the chain with one hand after attaching it is borderline cumbersome to impossible, so if it has been made too short initially you are in a mess. The adjusting also only works if not twisted or otherwise messed up, so you need to be tidy. For those reasons quite some aid climbers do like to use regular daisy chains.