Can we have smaller units of measurement?

At the moment we are able to filter proximity by Miles & Kilometers. I need to show results within 1000ft of a user's current location. I've tried placing a custom value of 0.18939393939 in the filter settings but it seems to have no effect and doesn't show in the block view. Not sure if I'm thinking about this wrongly or if I'm doing it right and this is a bug.

On another note and I should probably make another issue for this, I would like the user to be able to have the option to use their zip code, their nearest cross-streets or lat/long provided by their device as their location. Not sure if this is something within scope of this module though.