Zuti MDS Still Not Ready For Prime Time.

[AndyJWest]

...it's Maddox Games the job to fix that.

No it isn't. They are under no obligation to 'fix' anything. Particularly if it involves modifying 10-year-old software to suit more recent hardware, when they are already working on a successor to the application.

You purchased IL-2 as working software. It works, and by the standards of the computer games industry, it works well. That 1C:Maddox have continued to upgrade (for free) is a bonus, not a contractual obligation. If they decide that any upgrades they offer (via official third parties) must maintain the same standards as the existing software, that is their choice (though they may possibly be under contractual obligation to publishers over this). They have a reputation to keep, and may well consider this significant.