DPCM echo buffer does not respect new instrument sample layout in NSF export?

[Gumball2415]

echo buffer tests.zip
in the nsf export, echo buffer on DPCM does not seem to play the respective instrument's sample layout, instead playing the older instrument.

[Gumball2415]

due to the way the pattern compiler abstracts DPCM instruments and notes into DPCM sample indices, this cannot be fixed unless the method of DPCM pattern processing is rewritten entirely.

https://github.com/Dn-Programming-Core-Management/Dn-FamiTracker/blob/2c997736c1bd87bcee634d1225299fb0f4420617/Source/Compiler.cpp#L65C1-L67C14

DPCM instruments + note + octave gets translated into a sample index type via CPatternCompiler::FindSample() then storing the result in the note parameter, thus making echo buffer commands possible, but not instrument changes.

the only alternative is "baking" in echo buffer commands at compile time, but this may be impractical.