Toolbar won't accept custom collectors

[MGatner]

The User Guide outlines creating a custom Collector for the Debug Toolbar:
https://codeigniter4.github.io/CodeIgniter4/testing/debugging.html?#creating-custom-collectors

However, the Toolbar service takes a static $viewsPath from app/Config/Toolbar.php and then toolbar.tpl.php uses this to render a view template for each Collector:
https://github.com/codeigniter4/CodeIgniter4/blob/develop/system/Debug/Toolbar/Views/toolbar.tpl.php#L139

Therein lies the conundrum: $viewsPath will either be the default SYSTEMPATH . 'Debug/Toolbar/Views/' (where developers should not inject their own _packagename.tpl) or some other path which will lack the view templates for core Collectors.

The Guide states "display() should return a string of HTML" but it actually needs to return an array: https://github.com/codeigniter4/CodeIgniter4/blob/develop/system/Debug/Toolbar/Collectors/BaseCollector.php#L237)

My guess is that the User Guide is reflecting a step in the direction of making it easier to create custom Collectors (by directly return HTML from display()), but that change hasn't been implemented in the Toolbar class yet.