"In the A600 the CPU is soldered directly to the mainboard and cannot be removed. Thus the only way to install it is to clip it over the CPU, using a PLCC socket placed upside-down. PLCC sockets are not meant to be used this way, so this is really a bit of a hack and might not even work in all cases. Space around the CPU is quite limited, hence the odd shape of this board."
"In the A600 the CPU is soldered directly to the mainboard and cannot be removed. Thus the only way to install it is to clip it over the CPU, using a PLCC socket placed upside-down. PLCC sockets are not meant to be used this way, so this is really a bit of a hack and might not even work in all cases. Space around the CPU is quite limited, hence the odd shape of this board."
https://github.com/SukkoPera/OpenAmiga600FastRamExpansion
Definitely not contemplated during the design/spec of the PLCC socket, I'm sure!