Here is what security researchers have found regarding unofficial portable versions:
Despite its utility, JPEGmini Pro Portable has limitations: jpegmini pro portable
A "portable" application is software that does not need to be installed. It runs directly from a USB stick, an external SSD, or a cloud-synced folder (Dropbox/Google Drive). Here is why the portable variant of JPEGmini Pro is so highly sought after. Here is what security researchers have found regarding