For the purpose of institutional memory;
Colonialism over Russia, aka an idea I'm simply already to deeply in love with....
WI: Russia did not colonize east of the Urals
Judging by a cursory glance of these threads, it would be plausible for northwestern Europe's maritime powers, such as the Danes, Dutch, or English, to secure large tracts of Siberia for the fur trade. The southern areas of Siberia have productive farmland and the region is vast in mineral resources, so if they hold on to Siberia long enough to discover this, there could be an influx of settlers and things could wind up very interesting. It's a stretch, but the idea of, for example, a Dutch-speaking Eurasian Canada-analogue is insanely cool in my opinion.
On the other hand, I don't think the Chinese had much interest in Siberia, and they already had vast tracts of sparsely populated land west of the Han heartland. On the other hand, if the Pacific coast of OTL Russia remained outside of the effective control of the Europeans or of strong enough native Khanates, it could be appealing to a modernizing and expansionist Korea or Japan.