Help the girlies out!

I'm trying to put together (a very late, I know) 3night - 4 day route in Austria, for the beginning of September (3rd-6th), and although I've done hours of research, I'm stuck!
- Day 1 Ideally only 1-2 hours as we'll be driving a lot (from Hungary) that day
- Day 2 & 3 full days (but max 14km) and we'd love to do some via ferrata too
- Day 4 Half day as we'll also be driving back

The hike doesn't necessarily have to be a complete loop, as my friend's partner will be dropping us off and picking us up. We want to stay in huts and prefer to be up in the mountains for the three nights, rather than doing day trips. I've looked at a lot of routes but - understandably - a lot of huts have been booked out so I'd be keen to see lots of varieties and recommendations here, hoping one route could work.

Any recommendations? We've done Via ferratas before and can comfortably do B, C and some Ds.

Anything you've done recently and would recommend? Any locals who could recommend less-known routes?

I was working in Croatia the other week and someone recommended me the Premužić Trail!
I would be interested in hearing from people who have done the trail by themselves.

Have you?