Well almost all issues mentioned above have been resolved in the "Minecraft Seven.ttf" version 2 found inside Minecraft Earth resources, though it also introduces new typefaces for existing characters, such as "×" (multiplication sign).
Hi Douglas!
Currently the .ttf file is located at Minecraft.apk\assets\fonts\Mojangles.ttf and is not part of a resource pack, so presumably it is beyond customization.
However, just as what you have already managed to do, the fonts in spritesheet (image) format located at Minecraft.apk\assets\resource_packs\vanilla\font\ is manipulable through customized packs.
In default8.png, aren't the spaces in (2,12-16) and (16,16) left blank...? So I'm absolutely clueless about what characters they are linked to.
As for the pentagon at (8,16), I would make the wild guess that it may be U+2302 (⌂) or U+2616 (☖), but I don't see any point in their existence. (According to the arrangement order of Unicode, the technical symbol "DEL" should actually be in its place.)
In beta 1.16.100.58 (971610058), the font inconsistency persists exactly as presented in the original description.
However, it should be mentioned that this issue may never have impacted gameplay since Mojangles.ttf seems to have been deprecated and unused since its introduction into the vanilla resource pack. default8.png, on the other hand, has always been the source of in-game font rendering.
Steps to Reproduce: View
default8.png located in base.apk\assets\resource_packs\vanilla\font\
Mojangles.ttf located in base.apk\assets\fonts
with respective explorers.
Observed Results: Pixels are differently arranged for characters including f, k, l, √, α, * etc.
Expected Results: The Minecraft-styled typeface should have been the same (even across platforms, if that remains within the scope of this ticket; please refer to the overall consistent Minecraft Seven.ttf font file found in Minecraft Earth resources as presented in the Attachments above).