Using a negative $stem_inset prevents an ISO Enter key to correctly render the legend.

[dsz-dsz-k]

I tried to define a new profile, taking DSA as a source.
I added a $stem_inset = -3; statement to have the stem outset (I'll be using the cap with low profile switches).
When creating an ISO Enter keycap, I get this result:

When commenting out the negative stem inset, I get the proper keycap:

I guess the $stem_inset value must have an impact on how the legends are generated, but I really can't find the right thing to modify.

Any idea?

Thanks.