[NTG-context] [fontloader] does base mode support combining substitutions?

Hi Hans, when combining e.g. certain number substitutions like onum and pnum or tnum and lnum, node mode seems to work fine. However, those do have value in math mode as well which node mode does not currently support. For comparison, here is a test file: https://bitbucket.org/phg/lua-la-tex-tests/raw/93745dba31e23febb02191c039dea... Is there a way to define a font with the combination of, say tnum and lnum that will work in math mode? If not, are there plans to implement it in the future? Best regards, Philipp