The two potential roads seem somewhat equivalent to me:
Both scenarios end in a large centralised platform run by Meta and a small community that want to avoid a corporate platform.
I think it’s also wise to separate the effect of large corporate instances in the fediverse between effects on Mastodon (where users follow users) vs Lemmy/Kbin (where users follow communities). In the case of Mastodon, the effects of EEE tactics will be strong due to a more powerful network effect because it’s important that a particular person is on the same platform as you (i.e. this is a similar situation to XMPP and gchat). In contrast, you just need some people to participate in a Lemmy/Kbin community to make it worth joining, but it doesn’t matter exactly who, meaning that membership can be small and sparse but the community still has a meaningful existence (i.e like niche forums).
I can imagine a hacky way to anonymise voting would be to have a pool of fake user accounts on your instance. When someone on the instance clicks to up/downvote, a random fake account is used to make the vote instead. This would then kind of work like a vote tumbler and keep the voting anonymous but still work with activity pub.
Maybe activitypub is actually a bit crap and we should all be using something better like nostr though?