I would say that the main difference is that area denial against Russia would take the active agreement of several national governments and complicit agreement from several more - so is less likely or at least more likely to take time and be quite apparent.
I think the wild card here is Estonia. With NATO backing, they have increasingly distanced themselves from the Russia, reducing their dependence on them (as an example, they are working on de-syncing their electric grid from the Russian, syncing to the Western European grid instead). Should tensions rise in Kaliningrad area, I'd believe they would be very much 'go' for a countering NATO move, affecting the supply routes to and from Kaliningrad, if a move going as far as cutting off Saint Petersburg would be deemed too extreme. This would put Finland in an awkward position, as they would almost certainly be affected by the Russian counter-counter move, and Finnish policy has been that of being "de-escalating" towards Russia in international relations.
I've worked quite a bit on Baltic scenarios and they're just tough. Modern Europe can feel like everything is in range of everything and every force is relevant particularly as things like precision guided artillery and loitering drones enter modern warfare. No scenario can be considered small because theater level missile and air assets are immediately relevant, and the AAW battle determines so much of the ASW and ASuW battle. St. Petersburg will act to defend Kaliningrad, Murmansk will follow thereafter, and now you have Backfires and Iskanders and B-1s and everything in the air, and all you really wanted to think about was a few submarines.
I've tried to think of less interconnected situations and one workable approach might revolve around the severe decay of Russian ASW in the Baltic. If NATO submarine forces collaborated and made good use of mines they could probably shut St. Petersburg down completely.
Indeed the geographic and geopolitical complexity of the area is, in my thinking, a major reason why an all-out shooting war is unlikely in the area as of today. I think all the sides would be very reluctant to escalate the situation further instead of backing off should first shots be fired. Area denial weapon systems in Kaliningrad would be rather isolated. Further, denying the Baltic shipping lines from commerce, Russia would effectively isolate itself first (it is not the only transit route to the Russia, obviously, but it is a major one). Also, it would be rather extreme move to shoot at a commercial vessel transiting the area. However, as things get dicey, accidents can happen.
What I can see happening is an increase in harassing operations: violations of airspace, aggressive maneuvering by military vessels, increased submarine activity, and perhaps even some special operations, and some targeting of individual vessels for various "reasons". Indeed, when I find some time, I am interested to experiment with a few scenarios in the area.
My apologies, getting quite far from Donbass!