1.111B class .xyz domain costs some 1 EUR per year. You’re limited to <6-9 digits>.xyz format (e.g. 012345.xyz) but if that doesn’t matter for your use case then this is the cheapest solution. You can get these via Porkbun, etc.

I’ve tried a large number of apps in search of something to replace multireddits. Summit for Lemmy is the only one which managed to implement this under its multi-community functionality. The app is being consistently updated with new features and I do not feel like I’m missing out on anything other apps offer.