Loading using base to a point on the ogive that you choose, works for your specific situation ,means nothing to any other situation. And its not the standard definition for measuring cartridge over all length.
Works for you and give you uniform results, its not wrong.
I think the thing you should do is load and shoot a test batch with no change but the increased neck tension and see what the actual results are.
Theory says lots of things but real world performance is what matters.
Sometimes, little changes don't show measurable differences. Sometimes they do. and sometimes the change actually affect performance in some way.
ONLY testing in your gun with your ammo will tell you what does, and doesn't happen.
was wondering if more neck tension would lower my SD/ES since its holding onto the bullet for longer period time and inturn provide better ignition thus lowering my SD/ES
That's what theory says, but the real world results may not be a linear change. And small changes might not create a measurable result amongst all the other factors involved.
I'm sure you've noticed performance "plateaus" in handloading, where making a small change doesn't seem to have any result, and certain points where it does. These are the same in principle, but the exact point (and amount) of the change is specific to your gun and your ammo combination.
Load and shoot some with the (slightly) increased neck tension. If there's no (safety) issues shoot enough for a reasonable size sample, and see if you
need to do something more, or if you just
want to,...
Nothing wrong with just wanting to, if you're seeking something, you have to look to find it (experiment, test shooting etc) until you either find it, or find you're not going to get it.
Good Luck!