Hi and welcome.
We, the majority posters here on BITOG are on North American continent, and we have limited exposure to some other brand name motor oil such as Avia.
Granted, if they meet all the major European and industrialised countriy specifications (such as ACEA, ILSAC, API, etc.), one cannot say why not use it and see?
(*based on internet search: it looks like Avia is a Switzerland based oil company....*)
I have had dealings with some motor oils in Asian countries, and my biggest concern typically would be certain domestic company with their own branding (e.g. Malaysia, Indonesia, certain mid-east oil companies) that even though they claimed (based on labeling) to be certain standards certified (ACEA, API, etc.) up to the most up to date specifications on certain grading of their motor oil, but sludging up still seems to be of major concern (things that shouldn't have happened if their oil (at least their base oil blend) is stout enough and comply to the standards and requirements, IMO).
Good luck on your endeavours. See if you can find some major brand name imported motor oils such as Shell Rotella T5/T6, Rimula, Castrol, BP oil for diesel engines, Caltex diesel oil(another name for Chevron here in NA) or Chevron Isosyn equivalent, etc.,Or some other stout Japanese blended motor oil for diesel engines.
"Internet discussion boards act as echo chambers for conspiracy dittoheads" A.Allen