@Pginer-WMF Do you think the anchor/callout/triangle is oversized in MediaWiki theme with its base side width of 10px. I've always thought it's a tad too prominent and should probably be reduced to 8px.
In the OOjs UI documentation Apex theme is still featured as default theme, it features a 7px base side width.
I propose to go for a 8px base side width.
Current (as of v0.19.4):
The proposals look good to me, but I wanted to point out that there are different measures involved here that we may want to specify and make conscious decisions about: length of the sides, angles, and separation from the object. For example, if you aim at a 8px vertical rithm (maybe we don't need it here), the triangle in your example despite using an 8px side as a base is going to break the rithm because of Pythagoras.