There is no possibility to get an e-ticket from Interrail/Eurail for this reservation.

Only Customer Support might be able to change the delivery address. You can contact them through this form.

https://eurail.zendesk.com/hc/en-001/requests/new

Customer Support is currently overloaded with requests so you will probably have to be patient to get help. Please let Customer Support know what date your travel will start so that they can prioritise your request correctly. 

In fact these trains only have optional RES-so do not worry.

Do not expect any answer-overworked and understaffed.

If you cannot stand the idea of not having some item with car+seat nr on; do it by yourself for 3€ at oebb.at.