So then, Brent, you do not care what the coil bind clearance is, right?
You'll run a spring .25 off coil blind or .000 clearance, right? What ever it takes to have low seat pressure, right?
Conical springs produce lower valve mass and can help but, they can't negate the need for open pressure.
So, give me a example of a actual spring, for a 8K (500 over rev factor) engine, with 1.78 installed ht, and .600 net lift and we will say 150 lb seat pressure. You say you an have anything you want, right? Oh, I forgot, it needs hyd rollers so I don't have to fiddle with it. What's the spring number I want?
I'll give you a break and won't require positive rotating retainers 
We have ran 8k engines, for many years w/o conical springs. I would say, before you were born, even. As heavy a seat pressure as you had to take, to get the open pressure and longevity needed. Coil bind has to be addressed as well as fatigue.
For a street engine at 5500 or less, seat pressure isn't as important. Low lift and low duration, with longer ramps, won't get you into any area, where your gonna pull a valve apart or shorten valve seat life, beyond normal rebuild life. You can triple spring prices with conicals. That's fine, if you don't need the money someplace else. Each part in a engine costs money, there are a LOT of parts. I make my decisions of where I spend my money and I spend it wisely.
Correct coil bind settings, will lengthen spring life as that is where they are designed to work.
To answer the PO's question:
The main one is, would you shim the side with lower lift to get the same open pressure, especially if the lower lift one is the intake?
You want to set them at the same coil bind clearance, for best results.
I'm typing this slow because I know you can't read fast.
Brent, I note that you've heavily edited this post. I read most of it when out for dinner, with my wife, while waiting for dinner. To address one of the edited portions of your post, I was building a roller cam, 427, when you were in diapers. I also read with comprehension and know how to multiply.
Look up above. Look at what I said about coil bind clearance. Look at what WConley quoted me saying about coil bind clearance.
Does it look like I don't care about coil bind clearance? I routinely run .050-.060" and believe it or not, some spring manufacturers specifically want some of their springs at .100" CBC, so I do that sometimes too.
I'm glad you, at least are taking my advice about setting coil bind at .050 - .100, thank you.
NOT ONE engine builder looks at the open pressure only without looking at the seat pressures to make sure the valves don't float to eternity and if you think that seat pressure in a street engine at 5500 or less isn't important, you've got more to learn than what I thought. Go build an FE with a hydraulic roller at 5500 and tell me seat pressure isn't important when you're listening to the valves float.
I never said you ignore seat pressure, what I was referring to, is AFTER you pick a spring with enough open pressure and CB clearance, to keep the lifter in contact with the lobe, you don't have any choice on the seat pressure. Move one, you move the other, with the same lift or, do you have a way to change that, conical or not? I grant you conical springs, reduce valve weight and adding a LW retainer, allowing less open pressure and that helps but, there is a limit and I want to be sure the lifter stays on the lobe. Also, not everyone wants or can afford conical's. Good springs are not cheap and double that for conical springs.
You have, one lift, to control, per lobe, you need to set the CB clearance with that lift and that only leaves you with one seat pressure. W/o the correct open pressure, you stand the real and detrimental case of the lifter lofting over the lobe and crashing on the closing ramp and seat.
If your seat pressure is greater than you want and you think it may bounce on the seat, you change the rate of the closing side of the ramp, to slow it down.
I think you need to talk to a cam grinder and discuss closing ramp rates, it may solve some of your cam problems.
If a spring mfg says not to do something, I lesson and would ask why. Broken springs are bad. You also need to know what they are used for. Case in point, the Open Comp car (oval track not drag racing), I sponsored lessened to a drag engine builder and he talked them into his springs, it cost them a whole engine. Do your research, and ask questions, not all springs are created equal.
