Hi!
Thank you very much for your kind words.
Well, currently there is no way to do that from a front-end drop down. You can set a static primary or secondary results ordering by custom field – both numeric and string types.
It is possible to use the asp_query_args filter to force a custom field ordering programmatically, but that is the same as when you set it on the back-end.
We are however planning on adding an ordering feature as soon as the filters section of the plugin finally gets the rework done.