Weather binding - transform

Hello everyone!
Just configured weather binding with OpenWeatherMap and it works.
As I can see the ‘unit=’ does not support mmHg, so my question is what is the best way to perform unit conversion? Does this binding support JS transform or using a proxy item together with a rule is a way to go?
Thanks!

This binding doesn’t support transforms so you will either want to use a proxy item and a rule or pull down the raw XML or JSON from the site using HTTP and use a transform to extract and convert the data.

Thanks a lot, Rich.
I’m more comfortable with a proxy item. I’m not sure if I can avoid creating multiple rules for the same conversion task. Will appreciate if you could look into my question here.