@Skif-off 1.34 is due https://github.com/geany/geany/milestone/12 ... oh wait, missed it :)
Since its been several releases since Scintilla has been updated probably this indeed should be included in 1.34, not sure what else is likely to make it, depends on peoples time availability.
If anybody notices plugins that need changing to match this Scintilla then they should ping the maintainer I guess.