Yo @markdmac don’t be putting yourself down…I been using UD for a good few years…And yeah I was lucky in a way as I had been using powershell studio prior to that, so had sort of built a way of developing programs using powershell to get the job done. But even so it still took me sometime to get my head around using UD, and then there was CSS, and REACT and all these other new things I had to understand. Again not being a full on developer, I had to find out the hard way like installing a custom REACT plugin for firefox, then allowed me to press F12 in firefox and suddenly get a REACT tab which showed me all the data the various components on my page were holding, which then lead me to realise how important using an ID param on my components was to reference them with get-udelement which is documented here:- Select - PowerShell Universal
As I put in my first post I only believe your imagination is the only thing holding you back once you understand how to reference, and read components on your pages.
I see the master @adam has offered you help, which is the holy grail in my opinion, as @adam has shown me the light on some UD questions that I struggled with for hours and hours before plucking up the courage to be like why is this so difficult…But it’s really not once you understand a few core concepts…this stuff is documented, but like me you may find it easier watching someone actually do what your asking…I do not have multi forest so cannot answer that, I have used AD integration with dashboards but that was using plain old UD, not PSU, in thoery though this should be the same, just some names might have changed on some commands, its all here if you want a butchers:- GitHub - psDevUK/psUniversalDashboard: Powershell UniversalDashboard