Hi guys! As I've said earlier in the forums, apparently Publisher's Baseline Grid Manager is included in the code base of both Designer and Photo.
And, weirdly enough, this feature's corresponding button materialised in both applications, and it seems to be fully functional. However, when customising the toolbar, there doesn't seem any way to put it back there if it ever goes away (or if I actively delete it), nor any other way to access it via the menus, though “snap to baseline grid” is an actual option in the snapping manager.
Can you make this feature accessible by design, since it's already present in the code and seems to work just fine? Even if it's just as an exclusive for people who also own Publisher, in case you don't want Designer to cannibalise it or something? Or… did you mean to actually include as an accessible feature all along and just forgot to put it in the toolbar?