Join the mendix community slack
https://join.slack.com/t/mendixcommunity/shared_invite/zt-2bxnjb6qa-e_Slo5xssxq3WMJUzldgSA
And join the channel #studio-pro-mac-feedback
Hello Gareth,
You can report bugs to the support department, click right top corner on the question mark and choose then for contact mendix support, after you can choose to submit a request this creates a form where you can specify your bugs, depending on the criticality of the bug mendix will provide your more information.
For feedback items that are more like features you can post an idea in the community, you go to community and then on the left menu select idea and post your idea. Mendix reviews this backlog actively and tries to pick up the most relevant( and popular upvoted) ideas into their product backlog and development.
Hope this helps
Good luck