When you get to Flåm you can take the boat across the fjord and then join either sykkeleute 3 or 6 from there.
https://www.norled.no/en/maps-and-schedules/expressboat/sogn-and-fjordane/

I think taking route 6 over Sognefjellet and then at Lom head up the main road 15 towards Geiranger – Trollstigen – Åndalsness is your best option to combine Aursjøvegen. But a lot of climbing is required!

If you want to skip Åndalsnes then yes cross Sognefjorden and take route number 3 to Ålesund where you can jump onto route 1 to Trondheim and the North.

Both options are amazing and spectacular!