If I said - "The Pure Drive is supposed to be a stiff, powerful racquet." Well, that certainly sounds like I've never played with one. If I had played with one, I would know exactly what kind of racquet it is and I would say instead - "The Pure Drive is a stiff, powerful racquet, period."
I don't want to keep repeating what I said earlier, please read the second paragraph of the post you quoted.
Since you don't seem to understand it or maybe just don't want to make a simple acknowledgment that you misunderstood, think about the following case.
Someone tells another (who doesn't pick up his effort for a difficult part of a course), "It's supposed to be the hardest part of this course. So, you should try your best." (Btw, I don't assume that not trying full gut for pro one is like not trying one's best. I know I don't need to say this. But better be safe, right?)
Does this imply that the speaker does not know the course? No. Rather, what the first sentence implies is that it's a common knowledge shared by both the speaker and the listener that it's the hardest part of the course.
And that's the same way of speech that I used in the sentences. So, I'm not sure which is the case: do you not want to admit that there's such a way of speech? or Do you not care what I meant? In that case I doubt there's any point of posting about
my post. Or is it too hard to make a simple acknowledgment of misunderstanding?
In any case, I've always found that stiffer strings work better in flexible racquets and softer strings work better in stiff racquets. You need one to offset the other. Thus, I wouldn't recomment using full natural gut in the Donnay. In fact, cheap, stiff, Wilson Stamina is working fine for me in my Donnay. I think soft strings in a flexy racquet makes the stringbed feel way too mushy and also causes a loss of control because both the strings and the frame are moving (flexing) too much.
In my case, the racquet would feel too dead for me under such a set up. As I mentioned in an earlier post, what's missing for me is weight to balance out the flex, not a stiffer string. Maybe, I should question as you did if you've really played with this racquet since your preference is different from mine. Maybe I should undermine the authority of your comment by mentioning this is not even your main racquet....

Nah, not my cup of tea.
Anyway, not so long ago, all the posers like me used natural guts (though not you according to your post), the choice of pros. I wonder how we were able to play with those flexible racquets strung with gut. Maybe that's why my tennis is not so great to say the least...
(Just to make sure, no, I didn't and don't use natural gut because it was the choice of pros but because of its feel, tension/playing character maintenance. Again, better be safe...)