Best Merchant of Record for a multi-vendor ebook marketplace?

Hi Guys

i have a online multivendor marketplace for ebook (Digital Product only)

so ebook author can regjister to the marketplace and sell they ebook from my marketplace

we keep 30% and the author get 70%

till now we have costumer from EU, USA, UK and Canada i have use stripe till not but the Global VAT is a messy thing so i wanna use a MoR

Which is the best to use ? in my case because i read the lemon Squeezy and i'm not sure if they accept multi vendor or marketplace model

also reasonble fee for lower-prices product because are ebook are from 5-20$ and on average is 7$ x sales

also if anyone have a multi vendor marketplace i would love to hear they story !

Thnx