Find below a modified version of POI Exporter plugin for QGIS: 1) removes the default duplication of <desc> and <cmt>;  2) adds three additional custom fields to GPX format (Elevation, Comment and Link).

Under Windows, unpack to C:\Users\YOUR_USERNAME\AppData\Roaming\QGIS\QGIS3\profiles\default\python\plugins and restart the program.