I bought my Glock 20 partly for use in IDPA. (Mostly because I wanted a 10mm!) I have also used my 19, but only once. (I've only competed in four matches so far because of work and the kids.)
I was going to say this is impossible but someone beat me to it.
The safety on the CZ 75B and 85 variations only works when the hammer is cocked. When the hammer is down it will not engage, thus you can have the hammer down OR the safety on but you can't have both.
In the CZ 75BD (decocker model) I believe that the decocker only decocks the gun, it is not a safety.
) I have also used my 19, but only once. (I've only competed in four matches so far because of work and the kids.)