I think the biggest practical difficulty was the lack of fund. It’s a pre production problem that of course impacts production.
for example, a music label office had to be set up in a library. (See below)
I would wake up, do some groceries and make the food for the staff, fresh food would be bought during the morning by production assistants like croissants, pain aux chocolat.
Also we faced an administrative problem. One of the location needed an authorisation, the public basketball ball player court. We were already on the set waiting for the DOP. When he arrived at the gate he got blocked because of the equipment. We had to call different numbers at 8 am in august (holiday season) to find someone who would do an emergency request.
unfortunately we got told that we had to pay for it and wait 2 months considering french administration.... we couldn’t wait 2 months.
we found a solution though. 4 train stations later, in a basketball player court that we all knew because of where we grew up.
link to photos an d video https://drive.google.com/drive/folders/1jwBrXOb-h5TIUOHrSRF5YS6MGZNOUtIj?usp=sharing