Its all common sense though as well

Only times i will EVER put axle stands on the sill is when there is work on the rear axle wise

So for example having to change a spring - you need the axle to droop - you kinda have no choice but to go on the sill

Front - its a little different - If push came to a shove - i've jack on the rear arm bolt area and stick the axle near the middle part of the subframe if need be
I'd always keep the trolley jack with me on the side im on
Shud the stands fail - i might get away with the jack to rescue me

Ziggy