Do you have a limit in mind on how large you're willing to go? A brief bit of napkin math shows that, at 1KB per record, your largest view should fit within 100GB of memory. This is easily supported by Materialize and I can certainly understand if this exceeds your appetite!
If you're interested in reducing the size of the in-memory dataset, does your fact table have a temporal dimension to it? By default, Materialize stores data for all time (like a database) and you can write views in such a way that it will only materialize recent data (like a stream processor). Our co-founder Frank wrote a blog post[1] detailing how to do this.
I'm honestly not sure how TAIL-ing a non-materialized view would perform. Sounds like something that would be fun to test!
Happy to chat about this further in our community Slack channel if you have more questions.