[D] PhD application did not go well, considering research while working fulltime

My PhD application did not end up well, so with high probability I will start working in industry fulltime this summer. The job is still ML-related, but not a research role. I wish to keep myself exposed to research, maintain a connection with my current lab, and apply again next year. I figure the best way to do this is to continue doing research in the lab, but I wonder:

1. How feasible will this be? Do you know people doing this? What did they end up with? I know someone who did this mainly to wrap up unfinished work—he worked for one year at FAANG while doing research and went back to the same lab for a PhD in the next cycle. But I wish to hear more stories
2. The PI told me he is open to such collaboration, but will I get into trouble with the company? I will have an NDA, and I don’t want to get myself kicked out because of this. And if I were to publish something, what would my affiliation be?
3. If doing research is not feasible, what are some other ways to stay exposed to research and maintain the connection with the PI? He mentioned that he might launch a startup in this field, and if that happens, I would not hesitate to move over, but to make that happen I really need to stay connected and stay current in the field

Thank you for the inputs on this!