How many tiles the NGP can handle at same time ?

[winteriscoming]

I take these infos here : https://github.com/mamedev/mame/blob/mas.../t6w28.cpp

I put together a VGM test where I told it to write one note to channel 1 in the left register and a different note to channel 1 in the right register in the same frame.  Only tone writes to the left register have any impact.  If I only write a tone to the right register and not the left, I get what I gather is the default tone.  As far as I can tell, there is no way to have 8 simultaneous tones playing on this chip.  It's just 4 with some stereo panning options.

Now, I tested in this the emulator named vdmgr, so it is possible they don't have the correct implementation for the chip, but vdmgr's behavior is aligning with my expectations, and it aligns with the way that Furnace is allowing for composition for NGP.