In early 1944 NF will still rely on ground control and support from Flak and searchlights.
So first try to identify his target or target area.
Next break up the NF Units in Groups of 4 machines and direkt them to the target area.
Do not allow the Computer to assign NF to Targets. Do this manually, and wait till you get a confirmation, that the target is not a decoy, a fast flying intruder or a decoy. Flak will be your friend, you will see a message if Flak hits an enemy bomber.
As soon as you have identified a real target (Stirling, Lancaster, Wellington or Halifax), assign a NF nearby to engage.
There is no Need to go for Mossies, from my experience this is wasted time.
And yes, there is a danger to loose NF to Flak.