I never put the slow down kit in as I only did peas one year with the cts (the next year i had the sts) but there was some who thought the rotors bounced to many peas out the back. Its not an easy task switching back and forth so I was a little trepid to put it in for 150 acres anyway.
I could see a desire to slow the tines down though esp. if splits are excessive.
One thing my nieghbour said was the cts had a lot more power with the slow down kit in. Makes sense as with the tines going slower there is a lot more torque on them. I also was trepid about that in our high mog conditions. The gear boxes driving the tines seemed puny to start with and increasing the input torque would only hasten there demise.
No there is more then enough area and time to seperate the peas out even with the slower speed. There is more of a problem with the peas actually bouncing around and out the back end. hence the theory that slower tines will save some.
Personally I think a round bar concave would do more for saving peas then the slow down kit but... changing out the concaves for peas and going back to wheat is a big big job. dang these compromises.
Pea combines should be set up like corn or bean machines i think. small grain machines are set up differently then large grain 'bines and I don't know of any machine make that is easily switched back and forth. putting inserts into a round bar concave is a compromise people. If it was better we would all have round bar concaves in for threshing wheat.
In doing peas, make sure the straw is dry. If you start too soon in the morning and the overnight dew has not dried off the separating capacity will be terrible and the amount of cracks will be high. Seems to pick up moisture immediately around sunset as well.