The listattr and hlistattr parameters may not be passed/set correctly by the code to ever be used.
Niso on #mediawiki IRC is reporting that the attribute parameters are not working as expected. They may also need a space added to not clash them into the tag name.
[08:57] Hi, about the dpl and gallery, be glad for help, tried that: https://pastebin.com/CMeQDnWh, when im writing explicit the files inside the gallery tag its working, but when using the dpl inside that not working, i assume that related somehow to the parsing order
[09:23] wah (that complicated lol), something like that i guess? https://pastebin.com/A5Ktta1S, that seems to display to gallery at the default mode also