1. Leftward protrusion doesn't work. 2. I don't think hz is working in footnotes.
The font I'm using is Adobe Garamond Premiere Pro. If you think there might be a problem with the typescript, I can show you that too.
These two are related to font. Either show that something is wrong with default typescripts (lmodern, times, palatino, etc) else it means that tosmething is wrong with your typescript. But first you have to narrow down the problem
I take your word for it that it works for the default typescripts; therefore, the problem must be somewhere in my typescript, but I have no idea where. It is as follows:
I don't have the font, so I cannot test it.
I should not have been so fast to take your word for it. If I use the default LM fonts, I get the same problems---no leftward protrusion and no hz in the footnotes.
You can prevent notes from splitting across pages by
\setupenumerations[footnote] [before=\vbox\bgroup, after=\egroup]
The footnote may still appear on a different page. If you want to prevent that add
\setupfootnotes[split=verystrict]
This doesn't work. I'm still getting footnotes appearing on the wrong page.
4. Notice the overprinting near the top of p.2 c.1. That is a marginal note that should go into the right margin.
\starttext \startcolumns
\input knuth \input tufte \column \input tufte \inmargin{This is in wrong margin} \input knuth \stopcolumns \stoptext
The marin note in 2nd column is displayed in the 1st column. This is artifact of the way in which TeX constructs columns: first creating a long and narrow page and then splitting it into two. I don't know at what stage of the OTR are margin notes inserted, and if there is a workaround. Maybe others can help.
this is the first time someone needs it so indeed there is no mechamism
it's not that complex to deal with it (but i'd only do it in mkiv) gien time and motivation ... you can put a feature request in the tracker so that i can look at it when i'm reworking marging notes the mkiv way (first come floats)
Where is the tracker I should put this in? I have found another problem which is probably related. In the same sort of arrangement, two columns with margins on either side, I would like to place floats like this: 1. If they appear on the left side, they should end at the right edge of the left column. 2. If they appear on the right side, they should begin at the left edge of the right column. Using \placetable[inmargin] (my best guess), this works fine for case (2), but case (1) begins at the left edge of the left column and can overprint the right column.