Each post example you’ve provided is spam. This is because it does not ensure education and cannot publicly benefit anyone; for this reason, an extensively underutilized feature, DMs, should be operated.
For example three, however, I deemed it as appropriate because I think an addition in work deserves a bump post. If you have a sale, or additional work, feel free to bump your portfolio.*
* - Disclaimer: This tactic is heavily my personal procedure. I am not aware of its compliance with the Developer Forum guidelines; refer to a stronger Developer Forum figure informed with the rules for confirmation.
To answer your question, please refrain from providing any forms of feedback in any #public-collaboration:public-portfolios. It’s meant to showcase works in return for profit, not community satisfaction. I’ve made a post about negative feedback in the past, and how it should be avoided, and the same applies with positive feedback. Avoid feedback in certain categories: my advice is to avoid #public-collaboration unless you’re in need of its features.