you can read this thread as well. Seems like lots of good into. Applicble or otherwise I am not sure, but it MAY help your outdoor rides
MTB rides are more punchy so your doing more 80/20 is a good idea tho I would also argue that in order to be able to push (weekend), you need to be able to actually train to push too.
from your yearly data, youre doing 136/165 ~40m and 152/122 ~1.5h rides on avarage. That’s good you’re increasing your time spent on the bike. Z1/2 adaptations occurs > 90m (or so I read) so you also need to spend more time there.
I also have to say that nothing beats improvement vs time on the bike.