none at 4".

Here’s the closest I could find, at 3.5” - https://www.aliexpress.com/item/K-touch-I9-Super-Mini-Mobile...

There’s a ton more and some at 2.5”!

That's interesting. But seeing Mediatek SoC my enthusiasm is limited. Personally I want only something that's supported at least by LineageOS.

However with that price it's not bad. But for now when my Nexus 5x will eventually bootloop to a higher plane of existence I'll plan to buy last Xperia Compact in used.

Edit: in reviews people mention that there is no global version. So there's no Play store. I'll pass.

Oh and I forgot. I keep my hopes for Sharp Aquos R2 Compact. So far it's only available in Japan and I now only that it will be released in the end of April in India.

Is this (or any of the other, off-brand alternatives) any good at all? Does the battery last more than a few hours?

I'm not sure how I'd answer these questions, if I was in the market for a small Android phone. And frankly, it's more likely to be crap than not.

If that thing were any good, it would be selling like hotcakes in the United States. Another terrible Chinese phone.

Xiaomi devices are amazing and yet they don’t sell in the States. Could be another great Chinese phone.

That thing has 3G. Terrible screen resolution. God knows about battery life.