Not really a question. Not even much of a discussion, unless anybody knows the arcane details. I just encountered an interesting limitation while exporting my first watch face project.
Three devices only (descentmk1, d2charlie and fenix5x) have a special prgLimit of 1048576 (i.e. PRG size limit), but only for "watchFace" app types.
Found this intriguing. That is all.