set which anchors an auto attach glyph uses?

suppose i have a glyph that’s an auto attach of two non-mark glyphs. is there a way i can control which glyph’s anchor the overall glyph takes? the glyph wouldnt be meant as a ligature.
Screenshot 2023-06-11 213039.png

Edit the base glyph members, i, I, u, U to position the anchors at or near to the baseline.
u ogonek anchors.png

Let’s try a different example: How would I get the mark to go on the Z in DZ instead of the D?
Screenshot 2023-06-12 094647.png

No such character exists in Unicode, as far as I can tell, but you would add the ogonek anchor to the Z and then compose DZ ogonek from D and Z ogonek.

suppose i don’t want to have such a precomposed glyph in my font and just want to handle the combination of the DZ digraph and the combining ogonek - U+01F1 + U+0328
how would i get that sequence to go on the Z instead of the D, without making a separate glyph or making DZ not auto-attach?

I don’t think it is possible.

could it be in a future update?

and another thing, how did this happen, and how can i fix it?
Cadexium.fcp (1.62 MB)
Screenshot 2023-06-14 200751.png
Screenshot 2023-06-14 200812.png

The mark did have a top anchor, which is removed, but FontCreator is confusingly still thinking it is available. Then it can’t find it and fails to position the mark correctly. You should be able to fix it by deliberately adding a top mark anchor to the ogonekcomb glyph and then delete it.

Actually it will just work fine. Use this in the Custom Formula:
D+Z+ogonekcomb