.......and be able to stop the second hand for a few Seconds by the end of each lap without losing track of the total time. The second hand could jump back to show the total time after a press of a button.
Seems like a reasonable and modest request, but rarely found in modern cronographs. Often referred to as Rattrapantes or split second complication, but seemingly rather rare and expensive. Explain why, antone ?

 

Sorry for mis-spelling the last Word, it should (of course) be ANYONE

 

It requires more gears and pieces in the watch making it more expensive to build, and harder to design. The pieces tend to be smaller and higher tolerance due to needing to fit in the same space as a regular Chrono.

 

I was under the impression that's what lap timers were for? Hard to wear on the wrist but easy to mount on the dashboard

(thanks)

 

Those were meant for rallies, for a co-driver to operate - obviously there are a few issues with having a driver operate stopwatches at speed! In other forms of racing, someone in the pits (often a driver's significant other) would usually hold a lap-timing board, like this one shown in a Heuer catalog:

 

Not as hard to make as they have no clock in them. Also not cheap.