I don't use them but I've heard only positive things.
As to maximum amount you would keep with them?
I wouldn't keep cash in ANY bank.
Keep the minimal amount you need for transactions and put the rest in either investments or in treasuries so they are ring-fenced away from the bank's assets in case of bankruptcy.
If it's USD you can put it in SGOV/ICSH. Then you don't need to worry about deposit insurance (mostly).
Afrasia Bank was the past years very restrictive - they mentioned us back in 2023 even that they don't onboard any new introducers.
Already before this they have been at least more picky the Bank One Limited in Mauritius - this Bank is still very open on Transactional Banking for International Companies even for traditional Offshore Jurisdictions.
MCB (Mauritius Commercial Bank) as well however they want you to use their Wealth Management as well - in other words they are willing to bank you a classic Offshore Shell Company if you put 1M+$ in a Portfolio with them.
MCB is by far the best Bank in terms of Online Banking and Payment Tracking (SWIFT Tracker).
There is ABC Banking Corporation as a last resort option in the same class like Caye Bank Belize etc. - they still Bank you a Samoa Company without any substance however they require a Personal Video Call to explain every transaction even for a couple of 1000 $ - not really transactional but at least dedicated Accounts and reliable Correspondent Network - still better compared to a lot of Caribbean Shell Banks.