If RGB++ allowed that, we would not even have proposed this Rosen Bridge integration.
Not a thing: RGB++ is not a Bridge, it just allows to export CKB L1 cells such as tokens/NFT/Protocols/… to other chains or (expressed in better terms) RGB++ current implementation allows UTXO on other chains to control a cell/UTXO on our chain. That’s the same reason why we don’t have RGB++ BTC on Nervos L1.
Fell free to double check with @fgh in a separate thread such as Verifying ZCash Equihash on CKB