If you have more than 255 extensions already mounted, then util-linux-ng will report no free loop devices. Since the kernel supports unlimited loops, creating more may be necessary when using util-linux tools. I had a line of code that would create a specified number of loops starting with the first free one,, a line that could be put in bootlocal.sh so loops would be available after booting and using over 256 for extensions.
That may be a way to go when more loops are needed, as opposed to a specified amount pre-created in base.
EDIT: As of TC 3.0, the standard 8 are in base, the rest created as needed by busybox mount.