Yesterday, I was still intending to go for the latest tranche of T-bill and Singapore Saving Bonds. However, with new information today, I am forgoing both of them.
I chanced upon a comment on InvestingNote by kolakamia that OCBC Fixed Deposit Rate is at 4.18% for an 8 months tenure.

Upon checking the OCBC website, indeed they have a CNY fixed deposit promo rate as shown below.

It is a good rate to me and so I decided to make a placement for it instead of bidding for the latest T-bill.
As for SSB, the newest tranche 10-yr interest has dropped to 2.97%. What is not as attractive to me is the the first 6 years interest will stay at 2.84%.

While the rate is still higher than a few of my current tranches in the initial years, the different is not much. Hence I decided to just stick with what I have for the moment.