Its funny that people think that conventions for typewritten text built around the limitations of typewriters define what is “proper” in environments where typewriters and their limitations are not involved.
The old typewriter typefaces were monospaced, ie. every character was the same width, but this is no longer the case. Virtually all typefaces today are proportionally spaced, not monospaced. So it’s redundant to leave extra room after periods.
My comment applies to a few pedantics I know personally, who stubbornly double space after periods when typing in regular situations.