Personally I wouldn't mind the MQTT only route as that's essentially how I'd be using them, however it would be nicer if it was built in.
It's not really about being nice to have but rather the benefit vs. time to develop, test and support this feature. Normally there is a discussion on Github or Discord (or this forum). Then if there is enough interest from the community we add a feature request on Github and see who can implement it.
Note that there are numerous other ideas and requests floating around, so this will take some time. The only way I see to expedite your request is to try coding this as a custom plug-in first...
If there were more core2 users of openHASP that could go faster but I don't see that currently. Maybe it's a bit like the chicken and egg problem. I might consider posting about openHASP in the Projects section to gauge interest.