Noto fonts go universal! Download pan-Unicode, merged Noto fonts according to time of usage (current, ancient) or geographical region (South Asia, SE Asia, Africa-MiddleEast, Europe-Americas).
I think fontforge can be used to scale down the emoji font from 2048 units per em (UPM) to 1000 UPM but probably there is a good reason that the emoji font uses the higher resolution.
Currently failing because of mismatched metrics (1000 for other fonts vs 2048 for NotoEmoji). This must be fixed upstream.