If toggling hostmasking in realtime is not required, then servers do not need to implement quit/reconnect simulations and other workarounds, and
I'm saying: implement toggling, but do not fake any quit/reconnects when the "mask" user-mode is toggled. I see simulating "quit/rejoin" as excessive, a bad idea, and not needed, even when toggling is implemented. The simplest thing to do is to allow toggling, and discard the artificial assumptions you crafted and stated that clients and scripts may make. I'm saying "to hell with their assumptions"; as long as they are not crashing or blowing up, the limited number of users utilizing masking mitigates any effect.
various small problems do not ripple out to annoy client maintainers, script writers and end users.
Well, problems *still* ripple out. There is no such thing rolling out masking as a seamless change, it is inherently a change that will effect users. And if masking is FORCED it will effect MANY all users all at once, instead of just users who are interested in masking, and want to try out a new feature. It is best to stage changes such as this. Let users who want masking be the only ones to use it at first. At a future version, once users are comfortable with masking, consider making it the default.
If disabling hostmasking is not required, then servers do not need to implement matching for real hosts, basic users never have to question whether they are protected, technically minded users don't have the mental baggage of a parallel host namespace they may or may not see, and channel ops and harassment victims don't have to deal with Yet Another Way abusers can evade their bans and ignores, however rare it may be.
Some people won't want to be masked. Just like some people don't want to be +i. Their friends can't find them with /WHO Toggling it off/on while on IRC only makes sense, if it is necessary to join channels that reject masked users perhaps. I see being able to opt out as important. Until users have acclimated to masking, and updated any bot access lists to reflect their masked host, it certainly shouldn't be placed on them by default. It *WILL* cause immediate issues if forced or made a default. Some users who didn't ask for or want to be masked will be unhappy.. If making masking a non-default prevents that, it is a reasonable tradeoff to allow a reasonable relatively non-disruptive adoption of masking (compared to forcing everyone into it at once). -- -J