Medium range but very portable scooter

I do currently own a Xiaomi Electric Scooter 3.
After the scooter getting more and more part of my daily life I'm now quite often get to the battery being very low, eventually making the scooter almost useless because it can't accelerate and the slightest incline makes the ride come to a halt.

For my next scooter I'm looking for something with more range (As the ES 3 has ad values of 30 km range, I guess 50-ish would be fine) and a bit more power for inclines.

My wish for the next scooter would be the folding mechanism being a bit more smart. I often take the scooter with me on train rides, and as it is essentially shaped like a Tetra Pak (Wide handlebars at the back, high front assembly up to the folding hinge at the front) it almost never fits underneath seats and leaving it unfolded is the smarter option most of the times, even if it is forbidden in trains here. If there are scooters that solved this problem better (E.g. because the hinge is between battery and steering axle, not in the steering axle, or the handlebars being upright making it tall but narrow) - That would be great!

I plan to buy a used scooter and sell my current one. The budget is about 300-400€ used, but that is not a strict limit.

Everything else (like tubeless, suspension, Apple Find My, Apps, indicators, ...) is not neccessary, but I'll take it if it doesn't bang the budget.