Either way works. If the starter is small and you don't mind adding it to your batch, go right ahead. With larger starters, you're better off cold crashing in the fridge, decanting most of the beer off, and then pitching the remaining slurry.
By leaving starter in fridge yeast can build up their glycogen reserves.
Interesting. From reading Fix last night, glycogen reserves are built at the end of fermentation and are depleated quickly when stored. Are you suggesting that if the yeast are refriderated before fermentation is complete that the glycogen levels will increase as they prepare for dormancy?
Maybe it doesn't have to be refrigerated but leaving starter 8-12 hours after propagation should enable yeast to build their glycogen reserves (C. White, "Yeast").
Thus could fit into your read since starter propagation is also fermentation, so at the end of it yeast will increase glycogen.. but I'm not sure about expending reserves when stored tough..
Where did you read this?
We are only 10,000 years into beer... there are thousands of years left to go!
Things are bound to change!!