[kraka40]

Assuming you're using a DVB based tuner (DVB-T, S or C) you could simply increase the number of 'virtual' tuners associated to your 'real' tuners on the backend (I believe mythtv defaults to 2, but you could increase this to 4 or even 6).

That way mythbackend should use a spare virtual tuner to record the 'live' version of the 'scheduled' recording, keeping the 'real' tuner free to record your priority 9. Probably a good idea if you have several kodi frontends which might be watching the same show at the same time as they will each grab a 'tuner' to create their own live recording.

However, like you I'm not 100% convinced pvr.mythtv always makes the right choice here. I've a DVB-T and a DVB-S2 setup (2 real tuners with 2 virtual tuners each). I think I've had pvr.mythtv tell me I've no spare tuners when the DVB-S2 shouldn't have been recording anything, but I never investigated further. Not all channels exist on both transport media however, so it might have been correct operation. Also it was a while ago when the client was a bit more buggy.

Maybe pvr.mythtv doesn't prefer a 'virtual' tuner on an active source when it starts a 'live' recording?

If it doesn't this would probably be a feature which enhances future family harmony ;-o

I have 3 tuners available and am not able to add additional virtual tuners as it is a HDHomerun Prime. I'm pretty sure this is an logic issue in the mythtv or pr.mythtv code. Before a tuner is commandeered for live tv, all available tuners should be scanned .. if free, first tuner should be grabbed, and if none available, there should be other criteria available to prioritize the remaining tuners besides (grab the 1st one). My guess is that the first one is always the highest priority, so maybe a simple solution is choose the last one.