Gdtyjr

I have a document which was drafted using baselinestretch to set the line spacing. In order to prevent extra spacing in footnotes, I'm trying to switch to the setspace package.

Since the end result should be to compactify footnotes, I would expect the page count to either decrease or stay the same. Strangely, it increases. Part of the problem was the increase in vertical spacing around display equations. I was able to prevent that with the nodisplayskipstretch option.

The remaining problem seems to be related to a change in pagination behavior, as is visible in the following MWE:

documentclass[11pt,a4paper]article

%%%%%%%%%
% EITHER
%%%%%%%%%
renewcommandbaselinestretch1.3
%%%%%%%%%
% OR
%%%%%%%%%
usepackage[nodisplayskipstretch]setspace
setstretch1.3
%%%%%%%%%

usepackageblindtext

begindocument

newcommandmyeqn
 beginequation
 a quad quad quad quad quad quad quad quad quad quad quad quad quad b
 endequation


blindtext footnoteA footnote
myeqn
Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Etiam lobor-
tis facilisis sem. Nullam nec mi et neque pharetra sollicitudin. Praesent
imperdiet mi nec ante. Donec ullamcorper, felis non sodales commodo, lec-
tus velit ultrices augue, a dignissim nibh lectus placerat pede. Vivamus
nunc nunc, molestie ut, ultricies vel, semper in, velit. Ut porttitor. Prae-
sent in sapien. Lorem ipsum dolor sit amet, consectetuer adipiscing elit. footnoteYet another
myeqn
blindtext footnoteOne too many.

myeqn

enddocument

Using baselinestretch, all three footnotes fit onto the first page, despite the 1.3x line spacing of the footnotes:

On the other hand, setspace breaks the page earlier, even though the line spacing of the footnotes is only 1x:

Why is this happening, and how can I fix it?