Yes, that's OK. You pass is valid and the reservation will just say you have a pass.

Thank you for reply.  Can I confirm Eurail Austria Pass valid from Buchs SG station?  Or Feldkirch station?  If I plan to return to Vienna via Zurich Main Station I have to pay full fare for ticket from Zurich to Buchs SG/Feldkirch only and the remaining trip can be covered by Eurail Austria Pass?

I'm never sure about border stations, and where to find an authoritative answer. But I think @rvdborgt  will know!

Do you intend to stay on the night train and buy a ticket to Zurich? The problem may be finding a valid ticket, because Buchs is ‘exit only’ on that train (although Feldkirch is not).

Same potential problem if you will take a night train on your return.

I'm never sure about border stations, and where to find an authoritative answer. But I think @rvdborgt  will know!

Do you intend to stay on the night train and buy a ticket to Zurich? The problem may be finding a valid ticket, because Buchs is ‘exit only’ on that train (although Feldkirch is not).

Same potential problem if you will take a night train on your return.

 

Hi, from Vienna to Buchs SG will take night train.  We plan to get off at Buchs SG and travel to Liechtenstein before heading to Zurich.  From Zurich will take RJX during day time.

Buchs is the border tariff point between SBB and ÖBB.

Also see:

https://de.wikipedia.org/wiki/Grenztarifpunkt