and a lot more work!
I would definitely put a socket in for any chip I removed, but it's a big job to do it unnecessarily for all of them, and might cause more problems than it's worth.
At this stage of the game I would recommend getting a separate 512K board rather than upgrading a stock 128K given their rarity. In addition to the larger RAM chips you also have to install a mini-mux, which at this point likely has to be fabricated from scratch. Permanent modifications are required to the logic board which are not always successfully reversed. I've inquired about adding a simple toggle switch in the past, to switch the mini-mux in or out of the circuit, but simply haven't had the opportunity to do it. Theoretically you can install 256K chips and they will behave as 128K without the additional decoding circuitry.
I would definitely put a socket in for any chip I removed, but it's a big job to do it unnecessarily for all of them, and might cause more problems than it's worth.
At this stage of the game I would recommend getting a separate 512K board rather than upgrading a stock 128K given their rarity. In addition to the larger RAM chips you also have to install a mini-mux, which at this point likely has to be fabricated from scratch. Permanent modifications are required to the logic board which are not always successfully reversed. I've inquired about adding a simple toggle switch in the past, to switch the mini-mux in or out of the circuit, but simply haven't had the opportunity to do it. Theoretically you can install 256K chips and they will behave as 128K without the additional decoding circuitry.