Re: Advice on developing a load?
Interesting question.
I vote for the sled, purely because it should help you to remove shooter error. I wouldnt let it just free recoil completely, I would still use my palm/hand to hold the rifle and still use the proper trigger squeeze technique.
I believe it would help.
Unless you have solid shooting skills, and experience to back it you may just end up wasting range trips, ammo, even compromise potentially good results.
Keep in mind not everyone has this option, I just think its a bonus for those starting out development and learning as they go.