I’m not sure if its against policy, but from my limited experience with web dev, introducing content from other websites is tricky and can create its own issues.
About the size limit, have you tried using butler ? It allows to upload game projects of bigger size (I think up to 2gb?). If you want to upload a project of even bigger size, you can always contact support. In fact, it is suggested that you contact support in that case.
I hope this helps, hopefully soon a moderator will be able to provide more details about this.