Hello.
"What is the maximim size videos that I can use to get my exports to play properly?" - I never tested it. But I think that if you are faced with the problem of uploading a large file, then perhaps this is due to your Internet connection. Try temporarily disabling your antivirus and firewall, do not use a VPN.

"I can't locate the forum that users ask questions on. Can you direct me to that website" - You are in the right place.

I also recommend trying to upload the file to the hosting using an FTP client, and then specify the path to it in the program.