Ukraine is outside the legal reach of Russian and Belarusian censorship enforcement. RKN's blocklist applies to clearnet domains accessed from Russian ASNs; it cannot reach a v3 onion at all because there is no DNS to poison and no IP to null-route. Hosting in Ukraine adds physical and legal distance from the threat actor for operators whose audience is inside RU/BY.
Our Kyiv region nodes have direct routes to Russian residential ISPs through neutral peering, which means RU users with a Tor bridge reach the onion as fast as they would reach a domestic clearnet service. Average circuit time from RU residential to a Ukraine v3 onion is 6 to 9 seconds.