Signature Chain's webapp also uses IPFS as an option, at the moment, files are stored and pinned on infura and we limit the file size to 10MB, even though the current limitation on infura is around 100MB. The main reason is that we know their limit will drop lower in future so we rather anticipate it.
In the future we plan to also implement IPFS in the browser, which will allow every user to have its own IPFS node right in their browser.