Just tried, it worked normally. I am almost sure I tried all kind of variants in the past could not get any sound, now it just worked without doing much. Anyway cool. This needs to be tested to its limits.
Not sure if possible, a dream case would be composing in hackey trackey and sample player, then being able to export as MOD file (4 channel MOD* file of course, not more, keeping all minimal), with the used samples from hackey trackey sample player. How crazy would be that?

Then opening this exported MOD file in protracker clone, and it would sound same, or similar, its 8 bit variant. There could be 8 bit MOD export and 16 bit MOD export. Assumption is always in hackey trackey only 4 channels should be used as well... Just a side dream. There are lots of mid2mod tools, those I need to check out as well. But the dream technique would be for sure directly from hackey trackey and its sample player.
* 4 channel MOD file with maximum 31 samples allowed. hackey trackey could use notes from midi channels 2,3,4,5 for assigning to the 4 channels of MOD file...