KYB/Onboarding with PSPs in Thailand: Anyone facing KYC Latency issues?

As someone working in Payment Gateway, I'd like to ask for experiences from my fellow Fintech Founders.

Currently, we are accelerating our SME customer base expansion but are stuck with KYC/KYB issues with new PSPs, especially when connecting APIs. We encounter a lot of problems with the speed of identity verification (latency) for documents. Sometimes we have to wait for days, causing our customers to lose significant business opportunities.

The old PSP we are using can no longer meet the demands of larger volumes, so we need to look for new alternatives. I'd like to know if anyone has faced similar situations? And are there any PSPs that process quickly enough to support this, or are there any best practices for choosing a PSP in the $THB market for businesses that prioritize speed? Concerns about payout reliability and spread/fees are also factors, but right now, the speed of onboarding is the most crucial aspect.