This is such a good point, and honestly one of the more underrated strategies out there. The section order thing is not random - it's actually doing something real.
When I was prepping for my own attempt, I did a ton of experimentation with this. My logic initially was the same as yours - start with Quant, get some confidence, then tackle the harder stuff. But what I found was that my DI accuracy on mocks was significantly worse when I saved it for last. Not because I was "worse" at it, but because by that point I was already mentally fatigued.
The cognitive load thing is real. Data Insights asks you to hold a lot of information simultaneously, especially in MSR and G&T questions where you're cross-referencing multiple sources. That kind of working memory task is much harder when you're already two sections deep.
Starting DI first when you're completely fresh actually lets you read faster, track the question constraints more carefully, and recover from wrong-path attempts without panicking about time.
The only caution I'd add: if DI genuinely stresses you out, starting there can backfire because anxiety burns cognitive fuel even faster than fatigue does. So it's worth being honest with yourself about whether the alertness benefit outweighs the stress of leading with your weaker section.
For me personally, starting Verbal > DI > Quant ended up being the sweet spot. Verbal got me warmed up, DI came while I was still sharp, and Quant (my strongest) absorbed whatever fatigue was left.
Congrats on the 735 - and good timing sharing this before test season picks up.