I've been playing with the settings window for quite some time, today I finally cleaned the code a bit, you can check it out here:
https://github.com/merlight/ESO-LibAddonMenu/tree/edge (be warned though that I'm a rebase addict, so anything you commit on top of that might later go through painful merge conflicts)
First I have an important compatibility question
In LAM r16- addon panels are top-level windows with their own background. That means they could be displayed directly with SetHidden(false). Are there any addons exploiting that? Because if the answer is yes and their motives are legitimate, I'm kinda screwed - I was pretty deep into the whole revamp when I realized this, I already had addon panels in a container and had just hopped onto OpenToPanel to make it work with everything else I changed.
Now the less important stuff...
I separated the LAM window from ZO_OptionsWindow completely, it now shows in LAM's own fragment. That's done by "inlining" the previously used function ZO_OptionsWindow_AddUserPanel and providing custom callbacks. I renamed CreateAddonSettingsPanel to CreateAddonSettingsMenuEntry (because that's what the function does), and only call it when the fragment is requested for the first time.
I copied RightPanelBackground and enlarged the window & option area accordingly, but didn't change any option control dimensions yet, so it looks awkwardly empty. Accidentally, I discovered votan's new style branch a few minutes ago, somehow I always forget to git fetch --all. I'll check that out later. (Actually I already have a few questions regarding votan's fork, but they're not LAM-specific so I'll create another topic for them later
)
Addon list is now ZO_ScrollList, and there's a search filter box below it. Thanks to ApplyTemplateToControl (i.e. only on PTS) the box displays a hint when the box is empty, although I'm not sure whether it has suitable translations (SI_ITEM_FILTER_BY_TEXT is used in inventory item filter).
Edit: oh and panelData for RegisterOptionsPanel may contain additional .keywords for search, currently the filter searches addon .name + .author + .version. For example SousChef could set .keywords = "crafting provisioning", that way whenever I search for "craft" I get all addons with "craft(ing)" among their keywords, not only in their name. I should document that in source