I have to say, in my own experience, the Beige is the most sensitive to drying patchy from overwetting.
Conversely Chocolate ends up perfect no matter what you do to it.
You just have to make sure your sponge is only slightly damp and get on it far earlier than you would other brands but make sure its firmed up.
I work in smaller areas too, on an average sized bathroom I'd only do 1 wall at a time, less if the weather's hot.
I'd also add that the pigments in some of their colours, noticably beige and jasmine, really need a thorough mixing to achieve a homogenous colour, low speed small paddle mixer takes the sweat out of that.
UCP can be a pain to use, I only notice this when I use another brand and find it so much more user-friendly. Having 'cut my teeth' so to speak with UCP and learnt from past mistakes I find their colour range, finish and matching Silicon hard to beat so the pros outweigh the cons.
UCP white however should be renamed chewing gum grey and I will never use again.
BAL Microflex for white as mentioned previously.
Edited to say I replied to totally the wrong thread here!!