Looking for budget fountain pen shimmer additives that won't ruin my CMYK ink color mixes!

Hi!

I've recently gotten into mixing my own inks using De Atramentis Document Inks in Cyan, Fuchsia, and Yellow with their dilution solution. CMYK mixing is super fun and i wanted to switch it up with some shimmer. I bought different colors of Jacquard Pearl-Ex shimmer pigments and have been having fun with them with dip pens. (I know you shouldn't use it in a pen, but I could not contain my curiosity, and I did, and I ruined a pen completely...Thankfully, it was a cheaper pen lol).

I really want to add some shimmer to use in fountain pens. I've looked into a couple, but hit a couple of roadblocks:

1. Wearingeul Glitter Potions: I hear these have a great, clear suspension fluid that won't mess with my CMYK color formulas. However, they are pretty expensive for only 10ml, especially since the recommended mixing ratio is 1:10. I feel like I'll burn through a bottle way too fast.

2. Pennonia Liquid Shimmers: These are a bit more budget-friendly and super concentrated (only needing 1–2 drops per sample vial, meaning a bottle lasts forever). But I've read reviews saying the carrier fluid can slightly tint or muddy lighter/precisely mixed ink colors.

To be honest, my CMYK mixes aren't perfect anyway. The cyan is super strong while the yellow is pretty weak, so I already end up constantly tweaking my formulas to fix the colors. Because of that, I don't think I'd really mind the Pennonia tinting effect since I'm used to adjusting my colors a ton anyway.

For those who do a lot of custom ink mixing, which route should I take if budget and mileage are my top priorities? Is the Pennonia tinting effect easy to work around, or is Wearingeul actually worth the premium price tag?

If anybody has tried either of these, do you have any recommendations or tips? Thank you!!