With endowus giving a smaller 0.3% access fee for SINGLE FUND using the fund smart option, are there any reason why I should keep my multiple fund portfolio using fund smart?

Endowus or other platforms should be used only for asset allocation concept- meaning 0.6% in endowus. Why should you pay 0.3% for individual fund if you can buy an ETF via IBKR. Now the big question- with 0.6% endowus fees or 0.65% syfe or 0.8% stashaway- is it worth paying 1% for global ETFs or global funds (which may not beat benchmarks)?

For me- it's a huge problem- I started in all above three but will stop using them

No auto re-balancing of your portfolio by splitting. You will become the robo in the robo platform.

With auto re-balancing, the algorithm will automatically keep the percentages you set initially when you create the fund smart portfolio (portfolio fund allocation).

By splitting into single funds, you have to do the re-balancing yourself, which brings in the emotions of trading when doing the DIY re-balancing. This defeats the purpose of using robos, where robos removes emotion of trading and you just top up and shake leg. Hence, you will become the robo in the robo platform.

Unless you don't intend to re-balance your portfolio, then maybe the single fund method can save you some fees. Then you're probably just using Endowus as a means to access UTs that are not widely available to retail investors.

Having said that, if you don't intend to re-balance, you may then want to see if there are cheaper options to Endowus for access to UT (I'm not sure if there is as I don't intend to do this, hence no research done).

Just my 2cents worth. You do you.