Cam Break in?

How many have removed the inner valve springs for break in?
Is there any rule to this being required!

Flat tappet ? Aggressive lobes ?

Roller tappet & aggressive cam lobes!
valve lift
Intake .760 exhaust .721, 266/282 duration

What type of cam and springs? Real aggressive? That'll make the decision a little easier on whether to do it or not. Key is to just follow the provided instructions to cover your a** and mitigate disaster. However, if you decide to not remove the inner springs check the lifters to make sure they're free and can move in the bores. If one lifter stops its lights out! Use good oil and additive, etc. Most importantly prime the engine before you fire it, and when it fires your going to want that thing hitting the RPMs 2200-2500 instantly for good oil circulation for 20-25 minutes. Then slowly back off the throttle when that time comes.

If it were me I'd just take the time to break it in right by removing the inner springs. Taking the inner spring out is cheap insurance against a failure no matter what as there is less psi on it to maybe prevent that lifter from moving. Yeah its more work, but why risk it and you won't. have that sick feeling in your stomach or crossing your fingers before you hit the ignition button. Again, run good quality oil/additive.

Spring pressure is 300 seat & 750 open.

You don't need to remove the inner spring to run in a solid roller. There shouldn't be much "break in" going on.

If running a bushed lifter you will likely need to break those in with some rpm.

No cam break-in needed w/ a roller.

Yep, as stated. No cam break-in with a roller.

No need to break in a steel billet solid roller cam
If is a cast core break it in like any other new cam
treed in less thna40 seconds, good on all of those helping