> with further advancements, battery optimists expect the weight penalty compared to hydrogen at around 6,000 - 10,000 pounds.

The penalty is unbounded because one has a higher energy/weight ratio than the other.

So with hydrogen at ~ 130 MJ/kg and batteries at ~1 MJ/kg, if you need a mega Joule then the weight difference is ~130Kg. If you need 100 MJ then the weight difference is 13000 kg, etc.

So each energy will have a different penalty. Let's look at trucks.

Today a semi will carry about 1000L of fuel (~260 gallons), which is ~40,000MJ. That would require ~300Kg of hydrogen (plus supporting weight for the container, etc) or ~40,000 kg of batteries (plus supporting weight for coolant, container, etc).

Thus what is economical for cars may not be economical for semis. There is not a single weight difference between cars and trucks.

Whereas a big jet can use 20,000 Liters of fuel which would require 800,000kg of battery + weight of supporting infrastructure or ~6100 kg of hydrogen.

So it makes sense that the two biggest truck manufacturers would be very interested in hydrogen.

There are other costs to weight other than cargo capacity, both for freight companies and society as a whole. More frequent maintenance, slower speeds, inaccessible and/or altered routes, more accidents, more wear on infrastructure.