There exists some differences between the font file Mojangles.ttf and the original Minecraft font that actually shows up in the game chat box. Please refer to the attached images for comparison.

Specifically (and probably not limited to):

• Characters f, " and * do not match the actual in-game font.
• Characters k and l have additional pixels.
• Character = is displaced and is 1 pixel lower than intended.
• Character ≠ cannot be displayed unless unicode font is called.
• Some math and Greek characters including √, α, β, δ, π, etc. appear as bold formatted in-game, while thay appear normal in Mojangles.ttf.

After some searches it is discovered that those inconsistencies have persisted since the addition of Mojangles.ttf in BE version 1.1.

The SegoeWP.ttf is displayed well in 1.13 beta, yet it seems that the original MC font is still based on an old sprite sheet (default8.png) rather than the dedicated font file.

Hope it helps!