No...the more time was splitting 2-12 hour days into 3-8 hour days.
Not that any of this has importance ... did you change the subject from amendments? The amendment Collins crossed over for was more time to respond to initial motions. The 2 days -> 3 days change was done before the resolution was formally proposed, as far as the record shows, not an amendment. The changes were penned in before the resolution appeared on the record in the first place.
S.Amdt.1293 to S.Res.483 <- time mods extend time to respond
The Resolution text, S.Res.483 as actually proposed on the floor of the Senate has the 3 days for each side's argument.
This news article, "McConnell drops two-day limit on opening arguments", discusses the changes made before the resolution was formally offered in the Senate.