The exchange rate table in your blog refers to UOB Malaysia's website, but there's no Ringgit exchange rate in the UOB Singapore's website. So, it may be tricky as we don't know if eventually, they will use the UOB Malaysia's rate or the (unlisted) UOB Singapore's rate, since the source of the fund is originally from UOB Singapore.
I don't trust our local banks (DBS, UOB, OCBC, etc) as I had experienced before that their foreign exchange rates were usually not competitive. However, if the amount concerned is just a few hundreds (for spending locally), then it's not really significant.
Anyway, just did an instant online funds transfer tonight from CIMB Singapore to CIMB Malaysia at RM2.5271 rate. You can even conveniently check your CIMB Malaysia's latest balance and statement directly from the CIMB Singapore's Internet Banking website as they are both linked.