I know this doesn’t answer your question, but if you do decide to try other resins and want something with transparency between White and Clear, then Durable might be a good candidate. If you want to check out its color I’m sure you can get a sample from Formlabs.
I’m assuming you can’t simply thin the walls of your parts to compensate for the increased opacity of the latest White?
If you want to get experimental and push the boundaries beyond what Formlabs will support…
Out of curiosity, have you tried just printing it with the Color profile and no pigment to see what happens? Or maybe a custom recipe with just a small amount of White pigment? I’m sure @DKirch is right that reducing the amount of pigment from 100mL won’t work as well, but you might find a sweet spot that’s ‘good enough’.
I also wonder if mixing a little bit of Clear in with standard White might be worth a shot to try and nudge up its transparency?
Finally, while you can’t adjust the laser power on the Form 3, you could try choosing a material profile that has a lower exposure power. Here’s some old data on that front. Though I’m not sure how easy it is to “trick” the Form 3 to print using a different profile compared to their earlier printers. Might require a Universal Cartridge. And like I said, none of these suggestions would be supported by Formlabs.