Hi @Chris_B to request a feature, you would need to open a Support Case explaining the feature you would like to have. Support might ask you a few additional questions to fully understand the feature you would like to request. In the end, they will share a Public Issue Tracker link so that you can monitor the progress of your feature request.
It looks like I can create issues in the Issue Tracker. (image)

Should I not do that and instead add feature requests as Support cases? (image2)

@Chris_B , it is not monitored currently. Therefore, all feature requests has to be opened by opening a Support Ticket.
Yeah this isn't working...
I want to suggest a feature request (change in UI) , but can't...
I go to create a case (https://console.cloud.google.com/support/createcase etc etc), select SIEM, and the only subjects I can open a case about are
New Logtype, Other, or Parsers

Yeah this isn't working...
I want to suggest a feature request (change in UI) , but can't...
I go to create a case (https://console.cloud.google.com/support/createcase etc etc), select SIEM, and the only subjects I can open a case about are
New Logtype, Other, or Parsers

@Chris_B if New Logtype and Parsers are not matching what you would like to request as a feature, select Other and simply open a Support Case for that Feature.