one hint:
I download and keep the previous installer - in case of anything goes wrong and/or I have to uninstall and downgrade/go back to previous version in case of issues.
of course I still have the v16.3.6705 installer - but I am sorry, I think I am not allowed at all to distribute/make available any installer/version.... and I would suggest only install from trusted sources (software company).
but I agree, it would make much sense, that SmarterTools have an archive/at least always the previous version available for download!