First you must ask the dealer of the strap you have found and you like, how thick it is...
If it is more than 4mm probably it won't fit.. Don't risk it. Stick for up to 4mm thickness..
When the strap will arrive, the opening where the deployment clasp will fit, is 4mm because 4mm is the buckle. The deployment is 6mm so you will have to cut it from both sides 1mm in order the clasp to fit in.