Since I posted this, Ian from nostr:nprofile1qqsq9k04vahllseell55m74n3047y88pzlr0z5yany32st29fapqmgspz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz8nhwden5te0dehhxarj94c82c3wwajkcmr0wfjx2u3wdejhgtcv0vr5k (@ocean_lawyer on X) explained it to me last week like this:

Solo Miner: Datum pointed at Ocean pool.

Solo Lottery Miner: Datum pointed at their own address.

My swarm is def Solo Lottery. 😎