Singletrack Mountain Biking near Triglav, Slovenia?

We''re off to Slovenia 1st 2 weeks in August, staying on the edge of the Triglav National Park near lake Bohinj, just south of Triglav. Planning to do some MTBing and walking, including Via Ferrata.

I''m told mountain biking is not allowed within the National Park except on official MTB trails.
There don''t appear to be many of these trails; and I suspect not much of it is single track.
Is this all correct?
Is there really an issue with sensible and considerate use of non-MTB trails in this area? (bearing in mind this probably the busiest time of the year) - any of you have direct experience of this?
Can anyone recommend singletrack routes both inside and ****just outside**** the National Park area, to the south/south-west, near Bohinj?
Our preference is single track & we want to avoid huge uphill ascents unless assisted by ski lifts.

I''d like to cycle part way along the routes to Triglav (there appear to be essentially 2 from the Bohinj area - the 7 lakes route and a route via Voje), in order to make the routes achievable in a day instead of the normal 2 days when walking all the way. Have any of you experience of & comments on this? (yes, I know it gets very steep, rocky and exposed higher up. I shall be leaving my bike securely locked to a tree before this point )

Any recommendations on good maps for the area? - for both MTB and walking.

Thanks for your help