What caliber is your custom barrel chambered to?You can use the set trigger for an extremely light pull weight.
Don't tell CZ but I have a 527 with a 1.25Ib. trigger NOT using the set trigger. It is only safe as a target rifle but I by-passed the set trigger mechanism and adjusted the sear, replaced the conventional trigger spring to a lighter version. With a custom barrel I have cleaned 600 yd. targets with it more than once.
I was in a similar situation. Minimum adjustment and mine wouldn't go below 2 1/4lb. I also did the YoDave and settled at 1.5lb (plenty good for my needs). Some people hit the trigger lottery with their factory triggers, it seems.I couldn't get my MTRs trigger below 2.5# before installing a Yo Dave spring.
A friend installed it for me and he also did some polishing and got it down to 6oz.
I was in a similar situation. Minimum adjustment and mine wouldn't go below 2 1/4lb. I also did the YoDave and settled at 1.5lb (plenty good for my needs). Some people hit the trigger lottery with their factory triggers, it seems.