What is the best Islamic FD rate?

Considering zakat harta is 2.5%, Singapore's Islamic time deposit rate doesn't even touch that amount. CIMB is currently at 1.85%, Maybank at 1.7% for their 12-month rates.
If you have a larger amount e.g. SGD 50K or more. You would be better off diversifying your assets into other compliant instruments.
My long term portfolio is at a ratio of 40:60 I have a better ROR (rate of return) than 100% in compliant FDs. Or riskier FD with smaller banks in Malaysia.
With 50k, split 40:60, 20k invested at 15%, 30k in a time deposit in M'sia @ 3.1%, you'd return 6.46% per annum and not risk bursting the deposit insurance scheme.
That said, I opened a Malaysian Maybank account and a Singaporean Maybank account and transfer funds between them with ease to enjoy the excellent currency difference now on top of the 3.1% 12-month time deposit in Malaysia. Maybank has a good online presence compared to other Malaysian banks.
Diversifying rates also diversifies the risk of Sin as some ulama have stated murabahah used by Islamic banks are non-compliant.
These methods are based on my experience and opinions of the Islamic banking sector, should not be considered as financial advice.