Does this information also apply to the FAA tables?
Could anyone provide guidance on how this time span on the FAA tables (for snow, snow grains or snow pellets) are to be interpreted? Is this to be understood that in ideal situations the larger value (longer HOT) can be used whereas in less favourable conditions (such as high wind speeds, jet blast, and wing temperature well below OAT) the smaller value (shorter HOT) would be more appropriate?
Yes.
Yes.
And yes.
It applies to the FAA's interpretation as well. Upper limits of HOT for lighter precip, and lower limits for heavier.
Bottom line, common sense always applies. If you exceed your HOT you may still depart after a visual inspection (done in an approved manner, e.g. surface inspected from approved location--specific door/window, etc.).
Hope that helps.