The other day I discovered a font called Elstob that has an "Old-style punctuation spacing" mode that (among other things) adds significantly more space between sentences:
When Spacing is set to 1, the spacing between words and sentences and around punctuation marks is a good match for most books printed in the late eighteenth century.
https://psb1558.github.io/Elstob-font/
The documentation for that feature says[1]:
When Spacing is set to 1, the spacing between words and sentences and around punctuation marks is a good match for most books printed in the late eighteenth century.
[1]: https://github.com/psb1558/Elstob-font/blob/c9af23d3cbadf111...