NOTATIO

I have a 1956 Baerenreiter score of Bach's Magnificat BWV 243, and I went over it with a magnifying glass to get some details about the engraving.

Firstly: I do love the flags -- particularly the tiny gap before the note. One could argue that it's an accident from not quite putting the flag in the right place, but it happens so often that it is effectively 'the style'.
Secondly, the noteheads are actually quite large, going over the top of the staff lines.
I also love that one of the notehead tools has got a chip knocked out of it.

Interesting.
What is the staff size?

About 5.6mm?

A quick check of a Ricordi and a Breitkopf score from the 50s also show the same large heads. Perhaps it's a 50s thing?

I think rather the engraver tried to increase legibility for small staves, and only that size of punch was available. If he had 5.7 raster size that would be sufficient. So I guess, it is matter of making it bolder for small staff.
Here are some randomly taken Breitkopf scores for varous instruments (I guess staff size is larger) and none such oversizing is found. However, I can't zoom more than how it was scanned initially.

I don't know: I think I can see a little bit over the edge: I may be imagining it. It may be caused by ink spread, of course.

benwiggy wrote: ↑27 Jan 2021, 10:30 I don't know: I think I can see a little bit over the edge: I may be imagining it. It may be caused by ink spread, of course.

BTW, can you in Dorico choose another font for a selected measure, staff, system? That would be wonderful if possible. For instance, the reduced staff would have bolder noteheads, or entire emboldened font.

Sadly, no. I think you'd have to adjust the stroke in a drawing app afterwards.

Yes: I can see that the larger noteheads may be an 'optical size' choice for smaller staff sizes.

OCTO wrote: ↑27 Jan 2021, 11:14 ... can you in Dorico choose another font for a selected measure, staff, system? That would be wonderful if possible. For instance, the reduced staff would have bolder noteheads, or entire emboldened font.

It is possible and not too difficult in Dorico to change the noteheads of selected notes.
You have to select manually the notes you want to modify, right click, select "Notehead" then select the wanted "Notehead Set" from a dropdown menu.

To manually select notes may sound at first laborious but there are a few ways to select one or several bars quite fast.
Dorico provides all kind of notehead Sets for Bravura of course (Crosses, Triangular, Circled, Slashes and a lot more) but the user can create as many Notehead Sets as needed with any existing Music Notation font.
Creating a Notehead Set is a little bit convoluted but doable.

But I do not see any option to change the flags.