Thanks -- this is helpful feedback. We agree that Inky will be be most useful when it's available on "all screens," and we're working towards that goal. The architecture is designed with that specific goal in mind.
I could have my email everywhere with less worry over wanton snooping over my email archives this way. That would be a very valuable service.
It might require some compromise on data security if I wanted to be able to perform search on my archive via the web service though. Perhaps for people who are willing to give up zero-knowledge you could upsell a service which allows the data to be decrypted server-side in an in-memory store while they're logged in only. I'd be happy without search when using a browser client though.