I looked through focus.c for a value for this but couldn't find one to edit.
For this I used the new Full Res Silent Pics along with Focus Ramping (not Intervalometer). With 1 step focus adjustments and a 10 second delay, this was as long as a timelapse you can create in this mode. 101 frames. Is it possible to allow the counter to go up to 1000, or 999? Or a less practical way would be to enter a numeric value using the input modules, because it would depend on the user loading the module.