Won't do any good - have tried this over 8 years and have yet to have even one ride where someone didn't need to stop for fuel, even after being told that they need a full tank. It just causes a lot of frustration, so it's always best to stop.
Take what happened in Torquay, most of us fuelled up on the Friday before arriving at the hotel, but some didn't and we had to stop at the first pump before our ride on the saturday morning. In fact two bikes decided to go off and get fuel five mins before we set off because they said they were low on fuel and wanted to go right now...
We didn't see them again till we got to Princetown as their sat nav took them to a disused petrol station and they missed the ride. We stopped at a pump about a mile & a half away....
There is not a hope in hell that we will have over a 100 bikes fully fuelled and ready to go on the Saturday - not even if you email them twice, send them a letter, talk to them on the Friday morning, mention it again on the Friday evening and generally wave a flag about saying 'make sure your bike is fuelled' ...
...because invariably some people think that it doesn't apply to them...and they thought they could get it in the morning...