I can not repeat this. ‘Other roles access’ add-on should not apply restrictions to administrator role at all. And it does at my test WordPress single site istallation.
1) created ‘webmaster’ role as a full copy of ‘administrator’ role.
2) marked ‘webmaster’ role as blocked for ‘administator’ role.
3) revoked all URE capabilities from the ‘administrator’ role.
4) created new user with ‘administrator’ role and new user with ‘webmaster’ role.
5) logged in under a new user with ‘administrator’ role.
6) this user sees user with ‘webmaster’ role as expected, – restrictions does not applied for ‘administrator’ role by design.

Give me an exact scenario to repeat the issue or send credentials for your stage copy to support email address.