This is a suggestion for the distant feature, because it's unlikely that a large number of users will be interested in this, compared to the amount of work required to implement it.
In short, it would be handy to have the ability to run a Tor proxy on a computer so that Orion on iOS could use it to open onion links. You could even build the Tor client and proxy functionality into desktop Orion in order to make the setup process easier for users.
All of the existing Tor browsers on iOS are a pain to use, because they run a local Tor client that gets killed if the app stays in the background for too long, forcing you to reconnect to the Tor network all over again.