How Do I Limit Guest Data Usage on MAX BRI Pro?

We use our MAX BR1 PRO on a boat with limited expensive data while traveling. We have guests come aboard and do tell them to turn “low data mode” on for the wifi connection to our Peplink SSID. However they still use up data with apps etc. What is the best way to setup data limits (speed and total data) for guests while not limiting my own use? Is there a good FAQ or other in the manuals for this? I am somewhat familiar with the InControl2 system but please use some plain language. Thank you!!