SAP WM / RF related functionality is flexible to use both on RF device or SAP screen so keeping that in mind i can confirm that you can use the the RF for single process or multiple process it is not necessary that all warehouse activity should be on RF but from consulting perspective if you are configuring the ITS mobile for single process or multiple process configuration time remains same you need to make sure the Access port is installed in the warehouse for proper coverage
wrt to example yu mentioned "want to pick SUs that we want moved and then later download the SUs and move them"
The second part of the above statement "download the SUs and move them"" is not clear however regard the first part. if the requirement is to pick the SU and transfer to the line side then it is pretty much possible in RF you can transfer order for the line side and use LM05 /LM07 to perform the confirmation activity using RF