Very convenient having the option to allow GSX to handle all services after you chose to start boarding. However, they way it is now where GSX will start triggering the boarding service followed by catering and refueling, it results in quite a waiting time for no good reason when you don't have that many passengers.
My suggestion/wish is to change the order of services so even if you as the user picks the start boarding option, GSX will then instead trigger the services in this order:
1. Refueling
2. Catering
3. Boarding
This way, both the refueling and catering will be pretty much done when the passengers start boarding. Meaning, when the last passenger boarded the aircraft and the last bag was loaded, you're good to go.
Another benefit performing the services in this order is the numbers for PAX and fuel in the FMC (automatically fetched by GSX Pro from the SimBrief OFP) will be the correct ones much quicker. Meaning you will be able to go ahead and do the pre-flight part in the FMC with the correct weights etc while waiting for the last passengers to get on the aircraft.
The way it is now where refueling and catering are triggered after boarding, you end up having to sit and wait before you can finish the setup of the FMC. Unless you put in the numbers from the SimBrief OFP manually. Which would defeat the purpose having this performed automatically by GSX.