The Premium app subscription is for enjoying unlimited push notifications and avoiding having restrictions in the number of courses your users can download (here is more information, and a summary table here).
It won't make your downloading to go faster because, among other things, it does not depend on the app itself, the download speed depends on your course configuration (size and number of files to be downloaded) and server performance
Basically, the download speed would be the same for the Free, Pro, or Premium app subscription. You can do a basic test to check if the problem is at your server or course level, please login on our demo sites and try to download a course:
- URL: https://school.moodledemo.net
- Username: student
- Password: moodle
To improve the download performance, we are working on several performances at the Moodle LMS site (not the app). See this issue MDL-69952
Kind regards,
Isabel
PD We offer full refunds within 15 days for our Pro and Premium plans. If that is the case, please contact us from the Moodle Apps Portal, there is a Support tab there