Hi Rainer,
You can "kind of" simulate typewriter mode with this applescript.
It only has effect once your text overflows the window because it takes advantage of the fact that, when jumping around, BBEdit repositions the current line at ± 25% of the window height.
Note that there is a bit of blinking that I don't know how to avoid.
Save it to the Scripts folder and give it a keyboard shortcut like <Ctrl-return>.
--
# ~/Application Support/BBEdit/Scripts/0-[⌃↩︎]-[typewriter_return].applescript
try
tell application "BBEdit"
tell first window
if class of its selection is not insertion point then
return
end if
tell its selection
set vCharacterOffset to (its characterOffset) as integer
set its contents to linefeed
end tell
tell its first document
select insertion point before its first text
select insertion point after its character vCharacterOffset
end tell
end tell
end tell
on error aMessage
display alert aMessage
end try
--
HTH,
Jean Jourdain