If you were already intending to transfer points to Velocity, then yes, of course, now would be a good time to do it as you can take advantage of the 20% bonus.
In terms of whether you should transfer to Velocity of KrisFlyer, only you can answer that question. My personal opinion is that 50,000 KF points is worth more than 60,000 Velocity points. But if you’re focussing on travelling domestically, then you might want to transfer to Velocity. Again, that’s up to you.
I’d seriously consider a third option: opening an American Express Essential credit card with the lowest possible credit limit ($2000). It has no annual fee, and it means that you can keep your AmEx points when you cancel your other card without the need to speculatively transfer your points. Speculatively transferring Membership Rewards points (ie. transferring them without a specific redemption in mind) is never a good idea, but particularly at the moment.