Aspen,Samedan,Jacksonhole, Graz,Innsbruck all these airports are special airports, with special procedures, departing or landing. To these procedures are "attached" a maximum weight to operate from. Providers like Flygprestanda or Jeppesen are offering this golden number of MTOM for the conditions of the day.
America is peculiar because of TERPS criterion for procedure design which is completely different from the PAN-OPS 4 design. ( it is closer to PAN-OPS 2)
As a consequence, a lot of pilots are used to the 48ft / Nm 0.8% percent of clearance on departure, and were taught that way 20+ years ago; and JohnDyer you are right; you have to maintain a standard, because in many small outfits, nobody will do it for you.
The real issue here, especially in private Ops, is what is the boss accustomed to ? If being flown by people whom are disregarding the numbers, because engine never fails in real life, just in the simulator, it will be difficult to tell him suddenly that he can only fly by himself or fuel stop, or leave all these bags behind or a combination thereof, just because of a captain change. But like it is written here, you will find someone, always, that would load to the ceiling, fill the tanks, and go.
Airlines are a bit firewall to this ( but again, airline pilots have to trust the load sheet done by someone else, after all they did not weight these pallets), but they have other challenges.
The best piece of advice ( funny one) came from John and Martha King :
" And remember : Stay out of the Trees ! "