It's not the best solution but it sure is better than what we have now. If as a server admin you have more than one plugin with a permanent hud then you simply have to pick one or combine them. More often than not the plugins that require a permanent channel are gameplay changing plugins and thus you're not likely to have more than one anyway.
Perhaps what can be done is a check if there is a permanent channel assigned then use 3 channels for the plugins using -1. If not use all 4 channels? I'm just throwing ideas out there but it really is something that should be considered as just sending data over and over when you might only have to send it once every few minutes doesn't sound great.
The Orpheu plugin would be a better choice however as it gives you complete control over that channel, allowing you to know when other plugins use it and perhaps even blocking it or just overwriting it straight away.