I read this post a little deeper and I want to add one thing.Jaden,
A well reasoned discussion. However, your discussion involves a shaft change. Nothing stopping the further forward bridge with a carbon fiber shaft. Haven't been playing lately for several reasons but I played with the Cynergy low deflection shaft for about a year, bridging all over the place. Shorter bridge for normal play longer for the times I was too lazy to grab a bridge. I know how the cue ball will behave hit off center so no big deal when I use my typical, for me, about ten or twelve inch bridge.
I have never pried into your exact skill level but I know it is pretty advanced. What isn't an issue for you may be an issue for many others. Also, you are a pretty serious student of the game. Go to your favorite pool halls and ask the guys that seem to be always there what a pivot point is. Ask them where the pivot point is on their cue. I think the vast majority will give you a blank look!
I typically use a parallel shift for side spin. Sometimes a touch of backhand added for fine tuning of the cue ball's path. I have also used just backhand for long periods. Mixed a parallel shift with front or backhand english, tried half front and half back hand english. I like BHE least of all. Front hand english has a lot of potential but like a parallel shift needs to be used enough to make adjustments before putting down your bridge hand.
From a simple I suppose trigonometrical standpoint a back hand shift seems worst of all. It puts the stick angle side to side at a greater angle to the cue ball path than any other form of english.
We all tend to stick with what we are used to and after the experimentation I revert to a parallel shift but I think if I worked with it enough it came natural I might favor a front hand shift. You need to put in a hundred hours or more trying each variation of english and when we start combining them the combinations are endless. I even tried all three ways of applying english used at the same time for a few hours one day. Decided it was overkill.
Anytime we get away from centerline what we do involves trade-offs. Which ones we choose to make probably depends on what we are accustomed to. I often use a bridge I consider too long but that is just sloppy play. What I get away with is helped by being a centerline player. I mostly stick to within a half tip of centerline, which makes most of this discussion not apply to my play. Interesting exercise though and I always enjoy intelligent conversation!
Hu
While it may seem that BHE puts the cue at an odder angle to the original shot line than other methods, take a minute to REALLY think about it because I'll tell you right now that for the shot to be made with the amount of english that it is struck with, the lines of the cue will be identical regardless as to the method you use to put it there.
The ONLY difference, will be the relationship of the angle of your arm relative to your body and sight line. That absolutely does take some getting used to and some people won't be able to ever avoid chicken winging it with extreme side spin. Using BHE requires that you trust you are on the correct aimline line and to disregard the change in angle that rotating your arm out, or in, creates in your visual perspective since you lined up on the shot as though it were a straight, no sidespin shot, initially.
Jaden
Sometime not that long ago I posted a link to a youtube video of me doing a drill, where I setup the same shot 10 times going with center ball and then the face of a the clock going out to 3 o'clock, then backwards to upper right, midnight, upper left, 9 o'clock, lower left, 6 o'clock, lower right and back to 3 o'clock and then changed the balls positions and did it again. I did it all using BHE. I'll see if I can find the video and repost it here.