I block fed in two hour blocks: so I fed whenever baby wanted but only from one boob in any two hour period, then I'd switch to the other boob for the next two hours. Sometimes they would feed once in that two hours and sometimes ten times. Both mine were frequent feeders and stacked on weight. Dd was colicky but ds seemed to cope better with the oversupply and spewed and cried less.
this is what i do as well. my boobs cannot handle the 4 hour blocks and then i find that in that time the boob that i am using just produces more and more and then i start having like 3 letdowns in that time...

2 hours is my limit that i find works best for both of us.

and yep, went through a packet of terry flats today i need to buy shares in the terry flats factory hahaha