Another way to look at it. All the identifiers around the pots, switches, etc. NEED to be soldered. So, I’d print the schematic, and use a highlighter to mark all the pins on the connector which are referenced elsewhere.
Actually, I’d suggest careful soldering, rather than trying to solder minimally. You might want to buy a bag of connectors, and some cheap boards, and practice. I can’t imagine botching one of these, but I’ve been soldering forever.