Nes Emulators with Square swap mode

Hello
I would like to know if there are NES emulators mod that are able to swapping Square pulse (25% to 50% and 50% to 25%)
How in Famiclones (Ex. Messiash NEX, YoboFC, Famulator)

The next version of NSFPlay will be able to do this, though it is only for NSF, not a full NES emulator.

puNES 0.69 WIP and RockNES can do it