For messaging between loops, I recommend handshake items, see https://zone.ni.com/reference/en-XX/help/371599P-01/lvfpgaconcepts/fpga_storing_reentrant/. They are supported in SCTLs.
One thing we do sometimes to keep a loop running but not doing anything is adding an Idle state where it is checking for a message or some kind of change to change to another state.
I would recommend registers over occurrences. If you find yourself needing to go back and forth between two loops, handshake items help with that (e.g. you can read without acknowledge and then acknowledge later on when you want the writer to continue).