With only 70 GB of diskspace OP cannot safely have logs of value to support all the time. What I remember from various discussions with support is to keep logging to a minimum and (idealy) delete all log directories. However, I do keep some directoires (bpbkar, bptm, bpcd, etc.) while keep logging to a minimum. This atleast gives me "some" indication of what/where something went wrong - starting point of an investigation or a support ticket.
Once you have a support ticket open and they wants logs, they will always ask for verbose=5 logs. With verbosity at 5, my disk got used up by 25 GB in less than an hour when I was collecting logs for them! Hence, I can't keep verbosity at that level all the time (also save on compute and I/O).
So, if you are not having issues keep your logging to minimum and also remove unwanted directories. You can always create the directory when recreating an issue with detailed logs.
