Nice trees that don’t grow massive and have a small root system…

How about a fruiting cherry as opposed to a flowering cherry? They don’t grow as tall but if you’re lucky you might get edible cherries.

Apple trees, you’ll need at least two, see if you can find an old variety that’s local to your area. Or crab apples. Colourful at this time of year.

Silver birch or rowan if you want something not fruity.

I’d suggest always go fruit. If you don’t want it then donate it.

Apples pick and stew for pies and crumble through winter.

we have a smoke tree in the garden its lovely but it most defintiely looses its leaves in winter as i have to rake them all up. in fact the first ones have started to fall in this wind.

i cut it back hard most januarys to keep it in check, still probably 5m x 5m

kids love climbing up it

Fruit trees you can get grafted to a dwarf stock to help keep compact.

There is also a great selection of ornamental acers that have compact form and colour.

All will need you to keep on top of pruning so they don’t go beyond what you want, but neither will a few years neglect result in a 12m tree.

Apple trees, you’ll need at least two

Lots of self fertile ones available now e.g. https://www.victoriananursery.co.uk/Self-Fertile-Apple-Trees/