Pelham for cross-country/jumping

[ZoeEnglish]

Heather, I'm looking forward to trying the Pelham with the elastic curb you sent me! Could you answer a question for me that I think others might wonder about too? Is it safe to use the Pelham for cross-country work and/or jumping? My mare gets strong out in the field sometimes, and I'd like the extra control, but occasionally I have caught her in the mouth getting left behind over a jump and even with a mild snaffle, she gets very upset. I'm worried that if I caught her or pulled back too hard with the Pelham she might go ballistic. What's your suggestion, as I've never used one before?

Also, how tight should the curb be?

Many thanks!

Zoe