If EEG acquisition was made in 2 runs (5 min interval), can I first concatenate the runs and use the output as the raw data?

My EEG experiment was consisted of participants rating videos on a screen. My team decided it would be best to give each participant a 5-minute interval in between the task to not fatigue them too much. The problem is that for each participant I have now 2 datasets. I really don’t want to perform preprocessing on each individually specially since some steps work better with more datapoints (e.g. filtering and ICA). One option would be to concatenate both runs first and then organize them in bids as if they were the raw data (using .mff files from magstimEGI). My question is if this procedure goes against BIDS principles and if so, what can I do in this case. Thanks a lot!