XB-40 --> Is it possible to order custom tuning of the Auxiliary Reeds so that I can control how far each draw and blow note will bend?

Yes, of course.

You don't even have to busy yourself with notes. All you have to do is to indicate how many halfsteps you want your XB-40 to bend down in every single hole and note. Here a brief guide how to design your individually tuned Hohner XB-40:

You can reach the Hohner Tuning Designer by clicking the main navigation on every page.

Hohner Start Page
After the Hohner Tuning Designers Main Page appears, go to the navigation bar on the right and choose the XB-40 section:
Hohner Start Page

For there is only one XB-40 in this section, you have to click the single modell available here another time.

Now choose your notes from the flyout menues as on any other model the Hohner Tuning Designer provides.

Now, choose from the flyout , how deep the bend for this particular note is expected to go as a maximum.

If you do no selection, which is also possible, the bend will be adjusted to 2 halfsteps lower by default.

If you take f.e the 3 halfstep-bend, you can play all in-between-bends too,
however, the adjustment is only given for the last, the third halfstep. The in-between-bends are to be adjusted by your throat, as in any Richter harmonica.

Just work yourself through your tuning draft, adjust the possible downbends to your requirements and continue as you would do in any other type of harmonica too.