On IOS in Canada I have things in metric in both freeflight 6 and Pro.
I went into settings->general->language®ion and switched region to United States.
I thought about just killing the apps, but went all out and rebooted the phone.
When it came back on, I checked and both versions of freeflight showed imperial measurements. Good ole foots per second. Who measures with feet per second, really?
They could program an option to pick whatever weird measurement you want I suppose, but then probably just easier to move somewhere where you don’t have to be closeted about you choice of weights and measures.