Liquidity Aggregation for Small to Mid-Size PSPs – Any Best Practices?

We're a growing PSP focused on B2B SaaS and seeing increasing volume, but also a growing spread between our various payout partners. Dealing with multiple payment rails ($USD, $EUR, some APAC local currencies) means we're constantly juggling settlement times, FX, and effective liquidity. The overhead in managing these relationships and optimizing for the best net payout, post-fees and slippage, is becoming significant.

Curious if anyone has found effective strategies or tech solutions for aggregating liquidity across multiple banking partners/acquirers without committing to a single mega-provider for everything. Are there middleware solutions or operational models that have worked well for improving payout reliability and reducing costs for smaller to mid-sized players? Especially interested in minimizing friction for non-major currency payouts.