OOH OOH OOH, word!
Lemme preface my answer by saying screentone-moire on web is a near inevitability and that it can be avoided online by adding like ~6-8px of gaussian blur (assuming your manuscript is 600dpi; try more blur if your manuscript is 1200 or higher, or less blur if you've already scaled a layered copy of your file down to lower DPI) to a copy of your screentones before scaling down/exporting for web view. You can tell for sure than un-gaussianed, reduced screentones are gonna cause a moire issue when the dot pattern becomes unevenly shaped (some dots are circles, some dots are ovals, etc. Like if it doesn't look like an evenly sized dots or an evenly spaced grid anymore.)

So! 60LPI (lines per inch) at manga manuscript paper size makes for nice, even, textured-but-not-too-textured greys at magazine or tankobon (volume) size. But, the more you size down your screentones, the smaller the dots get, and the more "lines" of dots begin to fit in an inch, y'feelme. If you have Clip Studio Paint, you can tell it to do the math for you when scaling down your comic files with screentone in them. On the export screen: "Advanced Color Settings > Export settings for tone > Depend on Export Scale ✅"

For reasons, I scale down my comic files in Photoshop as layered PSDs with the screentones as solid flat grey cells (like I did for my recent mini-zine) so can make the new screentones with the increased LPI myself, after doing the math for what the new LPI has to be. TokyoPop popularized publishing English Manga at 5" x 7.5"; around 57.73% of the size of the original manuscript paper the mangaka drew it on, so when I want to print a comic I've made, I scale it down to 57.73%.

So yeah in the original CSP file, I use 60 LPI for tones just meant to be read as flat colors, but lower LPI for ones more meant to be read as textures/actual dots. To come up with the new LPIs I need based on the old ones I had originally, the mathematical formula is as follows:

[Manuscript LPI]*([Reduction % as Decimal]^-1)

We put the reduction to the power of negative one because, say you reduce a 60 lines-per-inch tone to half its size. You can then fit twice as many of the OG lines in an inch. 120LPI. If you reduced it to a third, you can fit three times as many, etc. Doing something to the negative one power represents that relationship.

So that formula for me reducing a 60LPI tone by 57.73% would look like,

60✖️(.5773^-1)

Which equals 104. I like to roundup to the next multiple of 3, so 60LPI at 57.73% size is 105LPI.

I export my CSP file as a PSD, in Photoshop, scale the whole canvas down by 57.73%, and then go to the grey layers I wanted to be 60LPI and have Photoshop make tones out of them at 105LPI.

I will make a video on this later, but if you want a plug-n-play Google/Excel Sheet that can do the math for you, lmk!!