What do you think?
I use a 34", 24 frets bass, no String Thru. Brass nut, no want of reshape/replace the nut for a extra-thick gauge.
What I think is that your expectations are unreasonable. You're bumping up against the limitations of the laws of physics...but you don't seem to understand them well enough to even realize that...
You insist upon using strings in a gauge that were designed for standard tuning...then you're disappointed when they don't work well for drop tuning.
You don't care to try the DDTs - which were designed to use for drop tuning - because the reviews didn't impress you.
And you don't care to compensate for loss of tension by transitioning to a heavier gauge of strings - because you don't want to make any modifications to or replacements of your nut.
Unless you're prepared to compromise somewhere (let's just call it a concession to reality), I'd say you're pretty much screwed.

MM