I am using a utility called SUMo (Software Update Monitor) which indicated that there are several users "in the wild" using v18.1.154. When I asked support about it, they directed me to the Forums to inquire about a/the Beta Program, but I guess there might not be one.
Release 18.1.154 is also available from the Mindjet website at https://www.mindjet.com/mm-win-exe and the release notes are available here: http://download.mindjet.com/MindManager_2018_1_154_for_Windows_Release_Notes_EN.pdf.
The release notes for version 2.1 of the browser application are available at: http://download.mindjet.com/MindManager_Browser_App_2_1_X_ReleaseNotes_EN.pdf
I must be doing something wrong as, after going through the "ordering" process for a trial version, I download the .exe stub which initiates download of the 2018.0 version, not 2018.1.
Checking for a new version from within the product says there is no newer version than 2018.0.
Is there a direct link for the .1 version on your site? Could you kindly point me to it directly, thanks.