Hi Jake,
We use Moodle 4.2 w/ Microsoft Authenticator (it was established June 20th and our sandbox was last successfully launched on June 18th). We have a Learning Management System Admin who configured the LTI / Activity Chooser (he calls it Activity Chooser so I just go along with it so we understand what we're communicating about). I know it is configured by configuring it manually under "Plugins > Manage Tools". From there we entered Tool Name, Tool URL, LTI Version, Public Key Type, Public Keyset, Initiate Login URL, Redirection URI. I believe it is configured to show in activity chooser and as a preconfigured tool. In the Privacy section "Accept Grades from Tool" is ordered by Springshare to be "Never". I have limited permissions so I'm not allowed to access administrative things or edit the LTI/Activity Chooser. However, we sat and went line by line and made sure the following information matched between Springshare's LTI Toolbuilder and Moodle's settings:
Tool URL
LTI Version
Public Key Type
Public Keyset
Initiate Login URL
Redirection URI(s)
LMS Hostname
Not sure this provides any more info but it is the best info I can give.