Now I am ready to start resolving this slow/hesitation to start when warm..
New camshaft position sensor, Bosch 0232 1030 50 eBay
New crankshaft position sensor, Bosch 0261 2101 70 RockAuto
New fuel gauge pressure tester, RockAuto

I will start with the new camshaft position sensor. This idea came from ZERACER plus I found the following on a Mercedes forum.

Intermittent starting – This is a very common problem if the Camshaft Sensor starts to fail. You may notice the car starts fine one day and then hesitates to start the next. It could also be that the car starts fine when cold, but if it warms up, it’s hard to restart it.

Hopefully, I can eventually report the solution to a slow/hesitation to start when warm.