AK, just curious. How much does your 31MI weigh?
The handicap reference weight for a 31MI is 1189. Are you below that? Is the handicap table wrong?
If I read the safety notice correctly, the weight limit is not 1150lbs.
Gliders that weigh less than 1150 can only add water up to 1150lbs.
If a glider weighs more than 1150 dry, then it Is allowed to fly at the higher weight, but no additional ballast allowed.
Sounds like some heavy motorgliders might get an advantage.

While some heavy gliders are allowed to fly from the very back of the grid at the Seniors in March, there did not seem to be any discussion here about the density altitude difference between March and May when the 18m is scheduled.

Nice of SLGP to host the event. Would have been nice if it were earlier when the density altitude would be better or if another venue had stepped up.