Weight calc/ext tanks 4.13.3-4.13.4
 

From sticky post on 4.13.4:
"- Fixed the old (incorrect) method of external fuel tanks weight calculation during flight."

Just for our common understanding, - please remind what was wrong with old calculation?

in previous fuel weight calculating in two time... when you attach fuel tank on plane( add weight of fuel tank) and when you drop fuel tank( minus weight of fuel tank )

now flying with fuel tanks must be not so inert ... in a while of flight time

If I read you right...
4.13.3 and earlier versions:
When fuel tank of 200 kg full capacity (just as example) is dropped in flight at any time, total weight of aircraft is reduced by exactly 200 kg. Duration of flight at this point does not matter.
4.13.4:
When fuel tank of 200 kg full capacity is dropped in flight, total weight of aircraft is reduced by <200 kg minus weight of fuel consumed>.
Right?

yes

not exactly ... now fuel from external tanks loosing weight during the flight on tanks.

early external tank was 200kg( like in your example) and you fly some about few hours and that 200kg have no changes ... and when you drop tanks you lost from plane exactly 200kgof fuel ....

now fuel consumption from tank has an impact on weight total weight

I see. This is excellent. Long range flights will be more comfortable now.