My first two tries with brisket were on small flats like yours as well. I'm assuming my thought process was the same as yours...rather mess up a $10-$15 piece of meat than a $30-$40. Foolish logic!
My first one was a mess...chewy, over smoked, and salty as the sea. I had yet to discover this place when I destroyed that piece of meat. Once I found the Brethren I did some reading and got the same tips you did, knew that the smaller pieces of meat were tougher to get right but thought, what the heck I'll try one more. I had just built my UDS and went after it. Turned out much better the second go around...flavor was better, not AS chewy, but still not was I was hoping for. So keep faith your second attempt will be better but, everyone here is right...the little flats will slip away on you quick, next time I'm going with a packer...it's more than I need, but with all the "leftover brisket" recipes on here...you can't go wrong.
Golden Dome UDS "[URL=http://www.bbq-brethren.com/forum/showthread.php?t=149301]Dorthy[/URL]" | ~22" Char-broil "[COLOR="Green"]Char-lene[/COLOR]" | iGrill | Supersonic [COLOR="Blue"]Blue [/COLOR]Thermapen
Where there is love there is barbecue. – Gandhi