Just tested your mission, but did not complete it. Some points....
I like the extensive Briefing and the three phaselines you provided, as well as the mortar support. The feeling of the mission itself was much different than my expectations. The defense line B (which I selected) was quite bare, just 2 AT guns, no fortifications and the bright orange Urals did not help immersion. Could you use the military green ones?
Soviet infantry did not come in waves, but only small groups which much lull of activity in between. No offence meant, but to me it felt more like battling some bands of insurgents and not the mighty Red Army. Somehow I miss the MG42s that were so importand to the Germans.
The reason for me not able to complete the mission was that I reached critical losses rather fast (at 32-35 % levels), with little cover (just the trucks) available, and not enough tools to cause the horrendous losses the Red Army suffered in WWII.
Enough of words, I illustrate what I expected with a little "editor-thrown-together" thing.
But great to see that you kept the motivaton for completing this mission!