I have attachments up to 40 MB. Imported from Evernote. Mobile client works for now.
It seems fixing this size limit is quite understandably not going to happen soon. I suggest dowloading on demand will be looked at, at first, as a temporary fix. Would help in my case, at least, for I could usually switch to desktop to work on those bigger files.
Plus, even some of the big players like OneNote, haven´t enabled on demand, at least not on Android. 
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