2.4.22 of GSE Finally has a solution for downranking of spells in GSE. While it works for English it was pointed out that in German “Rank” is actually “Rang”.
As part of GSE’s building process, it looks at the following https://www.curseforge.com/wow/addons/gse-gnome-sequencer-enhanced-advanced-macros/localization list of translations to use to translate the English phrases in the mod to the local language of the game. If Ranks do not work in your client, please follow this link, choose your language, find “Rank” in the left-hand list and replace it with the appropriate word for your language. This won’t come into effect immediately but in the next GSE build it will then be part of the mix.