It’s not straight forward to google how much of that is taken up by micropython, but it seems it may be about 600 kB pico memory - Raspberry Pi Forums. Also, the image e.g. ‘rp2-pico-20220618-v1.19.1.uf2’ is about 600kB; I guess that might translate into that much flash usage.
I calculate 2*1024-600 = 1448 kB.
However, under Thonny, the free space is reported as 848 kB.
I suppose there isn’t anything that could be done about it? I’m running a data logging application where I’m about 200 kB short of storage for data. With 1448 kB, I’d have plenty, but with 848 kB, I don’t have enough.
Looking at the schematic, it seems that GP10-GP15 are not used. This is SPI1. and there is free space on the back (if the usb-connector is on the top, these pins are on the lower left side. You don’t need all of them).
I had success with single-row female sockets. The pins of these sockets are just at the correct height of the SMD-soldered Pico. Using pins instead of sockets works also, but sockets are easier because the socket is lying flat on the pcb. Don’t use excessive heat.
This is a misunderstanding. Of course the lower side of the pico is soldered to the board. But you would solder the socket to the side of the pico, not to the top. So the socket is flat on the board (“plastic” as you call it), the pins are facing to the pico and the openings for the wires are facing outside.
As promised, here are two images. This is not your board, it is the badger2040w, which is physically similar. As I have written in a previous post, I would recommend a simple single row socket.
Of course you could also solder wires, or pin-headers or whatever. This depends on your soldering skills and use-case. But IMHO socket solution is the simplest. You could also add some glue to give some additional support, but that is not really necessary.
In the following images the socket is not soldered yet. And it is also not the right location for your needs.