I don't have that, but I have the impression that the minimum is still 1 Dt for 4 weeks, but you don't need 4 weeks of fuel?
So, you can have 0.25 Dt for one week on most small craft?
Note that the software is explicitly only using Core and HG.
No, there is no minimum for small craft regardless of weeks of fuel.
REVISED FUEL OPERATION TIMES
The small craft detailed in the Traveller Core Rulebook
and High Guard use the ship construction rule of a
minimum of one ton needed for power plants and this is
enough to run a spacecraft for the standard four weeks
of operation. However, it makes sense for small craft to
be able to use less than a ton of fuel for their tiny power
plants and this is what the Small Craft Catalogue does
to alter the operational characteristics of each craft.
As an example, the first small craft in the book is the Hopper, 5 dTon vessel with 8 weeks of operational fuel taking 0.1 dTon of volume.
For High Guard small craft that you don't want to change the fuel tonnage on, they recommend either converting the excess fuel space to cargo, or increasing the weeks of operation, which would give the Light Fighter 40 weeks of operation.
And we get back to the argument that if you are building a tool for the game system, it should use the all the rules of the system, not just Core and HG. At least make it clear that you are not using all the proper rules but only those from HG Update 2022.