There isn’t currently appetite for a transaction format change that would break the wallets, based on conversations in Prague.
The champions of the polls can provide that rationale themselves here on the forum and elsewhere. In the past, these poll questions became bloated with rationales that barely appeared neutral or balanced, and confused voters, so that’s why you don’t see them in my post.
In the particular case of the Sprout question, I plan to very strongly advocate getting rid of it ASAP and not waiting long to turn it off. Last time I was not very vocal about it, which was a mistake. Sprout is also slightly goofy for the protocol now after NU6.3, since payments can take place inside of it (unlike Orchard today), which somewhat contradicts our circulating ZEC principle.
This question appeared in the cancelled poll from months ago. The idea, as I understand it, is that some features depend on their advocates to actually implement (and audit, and specify) the changes, but NU7 itself should move on without those features if needed IMO.
Note that NU7 is years behind schedule.
The block time reductions are paired with a proportional decrease in the per-block subsidy, such that the daily issuance rate is maintained. The NSM questions in this poll are therefore independent of it.