Did Victor Campanaerts not win in the Namibian TT championship or something similar a few years ago?
I guess if you pay your subs and are a member of the national federation, you are entitled to take part in the event, but not to be eligible for the title. I think I remember Bialblockski (haven't looked up the spelling, probably wayyy off) taking part in the GB TT event.
I think Bialoblocki only took part in the RTCC National Championships, which (unlike British Cycling) allow participation based on residency. Campenaerts won as a guest starter in Namibia indeed, but didn't make the official result.
UCI rules say
"Participation in national championships shall be regulated by the respective national federations. Only riders who hold the nationality of the country for the purposes of the present regulations may compete for the title of national champion and the relevant points", so I guess this generally would allow participation for foreigners, if it says so in the national regulations.
Edit: found the Austrian rules as well:
"An den Nationalen Meisterschaften (ÖSTM/ÖM EZF [...]) dürfen auch ausländische Rennfahrer:innen teilnehmen, sind aber nicht wertungsberechtigt"
So in the time trial, foreigners can start, but are not
wertungsberechtigt, which is a bureaucratical term I struggle to translate. I don't think he should be in the result.