40 degrees initial!
Both of my v8's would die out if they were timed at 40° initial.
The same for you Mike; they should idle at 40*, just not at an rpm low enough because the butterflies end up falling underneath the transfer slots, as you back out the speed screws; so the fuel dries up, and she stalls.
If your transfer slot exposure is right, you can tug on the Vcan to 30* for sure, and if the rotor phasing stays good, then 40* should not be a problem. You will just end up with a very high idlespeed.
The opposite is also true. If your T-slot is right, then you will be able to retard the timing, perhaps down to 5*, but the idle rpm will slooow right down. As long as the transfers can keep flowing, and the power circuit doesn't start up, it will happily tic away at 550 or perhaps less depending on your idle-air bypass also working.
My 367, with the 230/110 cam will still pull itself at 550 rpm on a flat level hard surface; at 5* advance. By 500, I got a lil slip in the clutch. With the Commando 4-speed 500 is 3.6mph/parade speed, with 3.55s.
This is why I have a hi-volume oilpump,lol. and extra oiling to the topend, and drip holes drilled into the valley between the lifters, and drain-channels ground into my Eddies, etc.