What's the most appropriate place to discuss changes to Linuxcnc source code?

There are several ways of contacting developers as listed here
linuxcnc.org/community/
Many of then are often on IRC.
Thank you.

Actually, that is not such an easy question to answer.

1. Traditionally it would be the developers mailing list:
sourceforge.net/p/emc/mailman/emc-developers/

(Although it seems the number of people actively participating in discussions has dwindled drastically in the last couple of years.)

2. If you already have a proposed change then a pull request on github is the best way to get noticed.

3. Posting questions on the forum will certainly give you exposure to a sizable number of readers but how many of those would be aware of the whole picture I cannot say. Still worth a try though.

[edit]
Seems to me that this could maybe be handled in a custom kinematic component.