I wonder if they just expect you to move to a paid solution like tradevine or omins. Hence lack of feature updates on My Products. I for one would really like an auto comments option, for adding notes/Q&A

Yeah OP mentioned they're aware of that. They're looking for something more prominent, like a heading. I put in a feature request about a year ago and support passed it on...

Yephttps://help.trademe.co.nz/hc/en-us/articles/360007265051-Code-of-conduct Sellers Sellers agree to: Not subsequently spam previous buyers.

Go to one of your own listings > click on "seller's other listings" and the search box should be for your own listings only