Is the test result should be different in co-op multiplayer mode?
I prefer SP over MP by far. By the way, is SP more stable than COOP?
The differences between SP and local coop (the one you can start in the game) are very small in 2.46. Besides the mentioned additional (but somewhat confusing) options for coop, I noticed that AI tends to create fewer but larger squads in coop, which is good, while in SP bots are usually evenly distributed between 9 squads. In the previous releases, there were some bugs affecting only coop, but they should be ironed out by now. Other differences you may notice only if you start modding singleplayer.
On the other hand, dedicated coop (on a standalone coop server) seems to be less stable. It's affected by unique bugs, like occasional doubled and tripled gun firing animations and sounds, or crashes on Brest on Linux coop servers. Also, I don't like the way in which squads are manipulated in dedicated coop.
I've also witnessed random CTDs in SP, especially ... quite frequently in Meuse. Seems somewhat vehicle related, either fighting or cruising.
Could somebody else confirm crashes on Meuse? It's one of the "18 golden maps", rather extensively tested, and I don't remember any CTDs on it. But I must admit that I mostly test on foot, don't like armor
Note, it's better to do testing in the windowed mode (the launcher -> Options -> Video -> the "Windowed Mode" checkbox), then the game will perhaps show an error message which may contain some tips for the devs.