Pollen draws fit on the outside of the hive, the Flow system does not interfere with this at all.
If you can fit your pollen draw to a standard Langstroth box, then there should be no problem fitting it on a Flow Hive.
We have had some feedback that some pollen traps do not fit well with our Flow Hive Classic’s bottom board due to the raised landing board – read more on this, and which pollen draws/traps work well with Flow Hive Classics, on our Community Forum. There should be no problem using most, if not all pollen traps on a Flow Hive 2 or 2+.