I notice something that could be puzzling to users unsure how the process works. When I have downloaded a KMP file and want to install it, I double click on the downloaded file. I get the dialog if I want to install it and I click Install. Then my computer prompts me to give permission for the installer. When I give permission, I come back to the same install dialog, and it sits there for some 10 or 15 seconds while it is installing. There is no visible sign that the installer is working, so I might well think I need to click “Install” again.
My suggestion, when the user clicks “Install” have the program put up an “install in progress” notification while the installer is working, so it is obvious the install is in process.
I have Windows 10 and the latest version of Keyman 12.