Dear list,

Is it possible, in mkiv, to fine-tune the distance between a chapter head and a section head,  between the end of a section and the following section head, and between a section head and the beginning of the text?

My problem is the following:

In the revision of a thesis, to economize on processing times, I have done all corrections in the bodymatter, or even parts of it, using the setups of the entire project. But when I now add the front matter these above-mentioned distances have slightly increased, by 3 to 5 mm, with a rather devastating effect on the precise placement of large floats. At the beginning of a new chapter the difference is one textline (double line spacing), which does not seem a big deal but with nearly 500 pages of text it leads to nasty results.

In my setups I have for the heads

\setuphead[chapter][

header=empty,

page={yes,header,right},

number=yes,

alternative=middle,

style=\tfa \bf,

after={\blank[0.5cm]},

]

en 

\setuphead[section][

style=tfa,

number=yes,

alternative=left,

indentnext=no

]

Changing "after={\blank[0.5cm]}" to "after={\blank[0.1cm]}" or omitting it altogether did not have any effect. 

If the culprit is to be found  in the Frontmatter, or its specific setups, what should I look for?