I have a caad 10 along with hip,neck,shoulder and hand arthritis. I'm a lordotic 65 and found in the last few years that fit on the bike is a moving target and I have to mess with it every year whether I need to or not.
The bike shop left the steerer uncut and tipped the stem that came with the bike up
Saddle to stem drop's about a half inch and knee angle around 25 degrees.
I took the dimensions from the litespeed and put them to the caad 10.
For us old dodgers reach and stem height are key to comfort.
If you can sit on the saddle hands off and above the bars and almost balance without falling forward or back you're close.
Also you get older your trapezius gets weak, it helps to hold your head up, there's an exercise where
you gently raise your shoulders toward your ears that strengthens your neck.
The caad 10's a good fast bike for the money but for more than 3 to 4 hours riding the litespeed's ride is a little softer.
I do hope you get it sorted, as you know the smallest change makes a difference.