If you're careful, scoring drywall is no problem. A lot of people, I think, are not careful and it seems to be somewhat common for some people to use more pressure than necessary.
Due to the thickness, a knife is not an efficient tool for scoring drywall, which can invite even more pressure from the user. Past the paper backing, the mechanics of the "cut" seem to be more akin to a V-shaped snow plow in action.
The pressure and angles are the variables, not drywall, just pressure and angles.
While it's true high pressure is not required, it's also true that many people use way more than necessary. For that reason, and because of the inefficiency due to geometry, the general guidance should be to not use a knife for drywall, especially a steel that's vulnerable to lateral stress.
Obviously if you need to you can, but you need to be careful, especially because you might be doing it at your own risk without warranty support.
Maxamet is incredibly strong, just not against side to side pressure.
I'd also recommend a heavy sharpening to get behind any possible fatigued steel on the factory edge. I'm thinking in terms of crack propagation, perhaps to the point of being paranoid, but I didnt want any potential weak areas where a crack could get started.
My personal experiences with Maxamet have been 100% positive.