That has not been my experience (25 yrs using PS). I'm only pre-loading client data (e.g., DOD for clients who died in 2024, sale of personal residence on the Home Sale wksht, real estate taxes paid, "tagging" the 1099-R worksheet as a reminder to ask the client for that 1099-R b/c Proseries doesn't highlight the 1099-Rs that have no entries in the distribution field, etc.). We will also "tag" (F8) the dependents who are 18 or over - so we can ask the client whether the kid was in college or working as well as 15-20 other fields that we want to be alerted to when preparing the client return. We have a checklist that we reference every year that we use to preload a lot of client info (address changes that the client told us about in the summer, sale of a rental property, new Sch C if the client started a new biz - we can get that Sch C worksheet set up in advance as a reminder that we need that data, etc). 

I don't e-file any returns until early Feb, but "pre-loading" data during Nov-Jan saves us a boatload of time during tax season with relatively no downside risk of doing so. There was one year when the RE PIN numbers didn't transfer over to the State returns and that was a bit of a hassle re-entering those on 700 tax returns that were affected...but that was definitely the exception and all of that work was done in Jan when it wasn't that busy. I'm all for reducing key strokes during tax season, or "tagging (F8) fields where PS doesn't highlight when blank as reminders to me that I need that data from the client. I also tag the status notes so that I make sure those are reviewed before the return is finalized. 

We save LOTS of time pre-loading client data - definitely reduces key strokes during tax season because it's data that we can enter in advance. Less key strokes during tax season = less time = less stress.