Mimic one more feature on Famiclone?

[Yave-Yu]

It's... fluent square wave? This feature happens on Dendy, when game starts time2score in SMB1&3, these SFX is a fluent sound, not intermittent sound on original Famicom&NES. In NSFPlay, it calls Reset phase counter $4003-$4007, when uncheck it, square wave will become fluent. So if you implement this feature into Mesen, it would be wonderful! Thanks!