I will immediately buy BTC with my CBDC stimi (if it's not banned). Then, immediately self-custody it.
Discussion
I'd think by definition cbdc would be coupon-like and holders won't be able to buy what they want freely already, let alone buy investments with it, which BTC would be considered by the policy makers.
Also likely not able to transfer it to other people. CBDCs will most likely not be fungible.