Replacing the lockout chip

[K_Devel]

You're more or less talking about installing a switch to play only one cartridge.

I think there is more. Specifically unlicensed games. People reported several not working with top loaders which is missing it anyways. I believe Action 52 is one. I do collect unlicensed games so yeah, it was of interest to me to have this capability. Of course you guys would know better, but the speculation with some unlicensed carts is that the workaround for the lockout ON the board causes issues when the lockout is not completely present as the same is reported for pin 4 disabled systems.

[lidnariq]

Specifically unlicensed games.

The vast majority of unlicensed games were originally made to run on famicoms, not NESes, without the lockout chip.

People reported several not working with top loaders which is missing it anyways. I believe Action 52 is one.
[...]the speculation with some unlicensed carts is that the workaround for the lockout ON the board causes issues when the lockout is not completely present as the same is reported for pin 4 disabled systems.

The problem with unlicensed software and top-loaders is that almost all unlicensed software used a CIC stun circuit, while the top-loader grounds the pins for the CIC. As a result, this shorts out the CIC stunner, causing massive power consumption and several very unhappy power supplies inside the NES.

Simply disabling the CIC (pin 4) and/or removing it altogether (my first links in this thread) will not cause this problem, although your NES could have the protection diodes preinstalled on the board that would also make the CIC stunner very unhappy.