Thanks Hans.

I've updated the wiki. I'm wondering if there's a way to also control the
indenting? Max's solution removed any indenting, allowing the text for the
second paragraph to be flush. It looks a little strange to see text
indented next to a drop-cap. The test case is the same, but with the
addition of an indenting setup:

% SOT
\setupinitial[n=2, continue=yes]

\setupindenting[medium, yes]

\setuphead[chapter][
  after={\placeinitial},
  page=no,
]

\starttext
\chapter{one}
Kermit Ruffins

Meet me at the second line.

\chapter{two}
\input knuth

Meet me at the second line.
\stoptext
% EOT
This produces an unintended side-effect, as well, whereby the following
chapter heading is indented.

See https://i.ibb.co/n8cMkM9/unintended-indented.png

Cheers!