https://web.archive.org/web/20170130070756/http://www.fodxm.co.uk/fod_coffeezonesources.zip
Dn-FT crashes when I try to export 4_raindance.ftm to NSF.

https://battleofthebits.org/arena/Entry/Suppressed+Feelings/31620/
https://battleofthebits.org/arena/Entry/All+Bets+are+0ff/46078/
The first 2A03 square wave channel is transposed down when I export these to NSF and play them in NSFplay.
Based on a small sample size of .ftm and .0cc files that I tested, it seems like this only affects songs that use multiple expansion chips.