I like to figure out what all my PRs will be during the planning phase, optimizing for reviewer cognitive load and incremental development of shippable features.

I never need to stack PRs cuz I can work on the next one while the first one is under review and rebase once it's merged. I can see if the review phase is long at your company that this wouldn't work. But I prefer it if possible.

One thing I hate about stacked PR delivery is ppl go dark for a month building this whole new world and if you have architecture concerns in the root PR they will resist them because it means rebasing and changing all the downstream PRs as well. Bad incentives all around.