Any particular reason to NOT use GameSparks downloadables capabilities to host asset bundles?

While I see that (according to https://docs.gamesparks.com/documentation/key-concepts/system-limits.html), downloadables are limited to 20mb in size  - assuming I can steer around that, are there any other caveats?  

Is data transfer 'amounts' built into pricing?

So the fair use limit of 10MB per MAU pretty much makes downloadables unusable for asset bundles (that are of any decent size).

Gamesparks was willing to work out a price for additional bandwidth with us, but the pricing was much cheaper at any significant scale to just throw the asset bundles on an AWS S3 bucket. It's unfortunate because it would be more convenient, but if you're planning for mass scale ala f2p mobile game, it's probably smarter to go with a cloud storage host.