I know that it can be a bit of a pain, but have to say that making it required has the benefit that when someone is replying to a post they can see which device(s) you have, which can often put a question or statement in context.
I've found that It's especially useful, when communicating with new members, as it allows the long time members to quicky zero in and offer encouragement and advice.
I'll actually like the Location to be required as well, as often answers to queries are very much dependent on location.
Perhaps a small note besides the fields suggesting putting none / searching when a new member registers
