I think I only have one suggestion in mind that would be to group boost stacking in D6/7/8 as separate questions instead of one because the boost stacks work differently.
In D7 for example you can just stay back, gold drift and then come back from behind near the end. Means you can just stay behind most of the race then come back and win. In addition to that, the basic “behind” race boost is relatively stronger than in D8 and D6.
In D8 by contrast, you need to lead (and be good enough to do so) then you need to get gold drifts while leading and not hitting walls and then you still have to time the fallback just perfect to stack the boost. It is much harder to pull off and requires many different type of skills and timing than D7’s. It’s designed that you need to be really really good before you can pull it off. They are very different systems. The only place where it’s relatively easy is to do is Hakone and Lake Akina and even - and even then it wouldn’t work if you weren’t good enough to lead your opponent in the first place.
Can’t rememeber how it worked in D6 although I guess it would be a be a hybrid of the two based on how those games worked.
By having the question separated in three, you can still measure if someone dislikes all three systems (they’ll just repeat the answer three times) but if someone likes one implementation of stack but not the other, you will also be able to measure that as well. I for example like the boost stack on D8 but not D7 so under the current form I can’t give my full separation of answers since I have to judge all three systems in one reply.