This is not a technical limitation though. It's a policy limitation.
In theory, a name-constrained intermediate for `.example.com` has no more authority and poses no greater risk than a wildcard leaf certificate for `.example.com`. In both cases the private key can be used to authenticate as any subdomain of `example.com`.
But, name constraints are verified by relying parties (the clients and servers that are actually authenticating remote peers using certificates). It's hard to be certain that everything has implemented name constraints properly. This is, ostensibly and as far as I know, the reason CA/Browser forum hasn't allowed name constrained intermediates.
At some point it probably makes sense to just pull the bandaid off.
In theory, a name-constrained intermediate for `.example.com` has no more authority and poses no greater risk than a wildcard leaf certificate for `.example.com`. In both cases the private key can be used to authenticate as any subdomain of `example.com`.
But, name constraints are verified by relying parties (the clients and servers that are actually authenticating remote peers using certificates). It's hard to be certain that everything has implemented name constraints properly. This is, ostensibly and as far as I know, the reason CA/Browser forum hasn't allowed name constrained intermediates.
At some point it probably makes sense to just pull the bandaid off.