I think there might be a misinterpretation here on your side, at least from my personal point of view. I think that you are probably not insensitive to mineral levels, I think that mineral levels are highly overrated within this forum and that you might expect more from it than there actually is. We can start with this chloride/sulfat ratio thing, which is actually not how this mineral thing works and could end up with promoting HIGH levels of minerals for certain British styles in general, which is again, not how these things work.
Let us just assume that there are sufficient Ca levels, so that the yeast is happy and can flocculate as intended. This usually also means that sulfate and chloride levels are at about 100 ppm. Bam. Sweetspot, do not change this unless you have a really good reason to do so. If you want tp brew a specific historic IPA, that might be a good reason. You will end up with a certain twang or accalerated bitterness/dryness, however one might try to describe this strange elevated sulfate taste, but that is certainly a part of this specific brew (which I personally despise).
But if you are brewing anything else than a beer that sepcifically needs these HIGH levels of minerals, there is little to no reason to go that high, as it can easily destroy the beer, at least to my palate. I have made side by side tests with same brews but different mineral levels, have tried the "dosing some minerals directly to the beer in the glass" test thing, always the same results (again, other palates migth differ).
So long storry short, I would not be convinced, if I were you, that verdant is the reason for the tartness until I have brewed a beer without these excessive mineral additions that still has this tartness. Especially as you seem to be the only one here who made this experience with verdant.
ALkalinity however.... that has to be managed correctly. That one is important.