Anyone else hitting a wall with payment processor KYB for novel fintech?

We're trying to onboard with a new PSP for our niche cross-border payments product, and the Know Your Business (KYB) process is a total nightmare. It feels like they're just running down a checklist designed for traditional e-commerce, not a regulated financial service with a unique flow. Constant requests for documents that don't quite fit our operational model, then weeks of radio silence after submission. It's slowing down our pilot significantly. Are other founders experiencing this with existing payment rails, or have you found any providers more adept at handling non-standard fintech applications without the glacial pace and repetitive back-and-forth?