Holes that are not given an ECAD_HOLE_TYPE parameter value are exported as PIN type holes in the IDF (and I presume, IDX) file.
Most holes specified by MCAD in a board design are mounting holes, not pin holes. It would be useful to be able to set the default value when exporting so that users don't have to manually edit the ECAD_HOLE_TYPE parameter for each hole they add to the board. I would suggest adding a config.pro parameter to set the default type as follows:
ECAD_DEFAULT_HOLE_TYPE (pin*, mtg, tool, via, other) where PIN is the default to maintain upward compatibility and "other" is any user-defined value (to conform to the IDF 3.0 specification).