JazzCat used the Echo DSP in a couple of songs, e.g.
Diary of a Common Man. Note that some DBM effects (in particular portamento) are not 100% compatible with Impulse Tracker so playing the module through OpenMPT will break some of the guitar melodies. However, they will sound as intended when playing the song through libopenmpt, because then no internal conversion to IT format has to be done.
The LED filter command in MOD has mostly been used with parameter E01, i.e. ensuring that the filter is turned
off, because it's terrible. The filter is off by default in OpenMPT so you wouldn't hear a difference. I don't know of any module that would willingly
enable the filter. There is no good reason to do that unless you like muffled sample playback.
