Before you run out and buy another rod- try to use your 9 footer and enjoy the extra length for mending and reaching across seams. I can’t think of too many places where I couldn’t roll cast a 9’ rod but a 7 footer would magically make things work. Specialized rods for brookies are kinda silly IMO and unless you’re fishing classic cane anything less than 7 foot you might as well just use a spinning rod.
To the OP...
Think about the above comment and what I said about using an 11 foot Tenkara Rod at MANY Pocono blue lines.
First off, with a Tenkara rod you are using a fixed amount of line which is most often the length of the rod. That means with an 11 foot rod, the maximum distance you can cast is around 22 feet. That doesn't mean you can't go shorter so at more than a few tighter Pocono blue lines I'll use 6' - 8' foot line.
That being said, I'll never forget the first time I fished a Tenkara rod at Hickory Run versus the many times I fished there with a conventional 6'6" 3wt fly rod. I got into more trouble with snags on my backcast with the 6'6" rod because I was lengthening my reach because I had a reel...
And could...
With the Tenkara rod, even though it was longer, unless I changed to a longer line I could ONLY cast 22 feet (or less) which was WELL within the normal distances I fish at those streams. That's also outside the range of backcast snagging tree limbs.
However, the REACH I had with the 11 foot rod allowed me to guide my fly DRAG FREE through channels and chutes that was impossible with my beloved 6'6" 3wt.
I'll also never forget the time I decided that there was no better rod for ME to use than an 11 foot Tenkara rod at places in the Poconos where I used to fish a 6'6" - 7'0" 3wt.
Bottom line, if you fished a 9 foot conventional rod and put your finger over the line so you only had 9 - 10 feet of line & leader past the tip top while false casting; as long as you had overhead clearance, I bet you would stay out of trouble better than if using a shorter rod and trying to overcome the distances by aerialiizing more line & leader.
IMHO - Reach trumps almost everything when it comes to fishing small rocky, obstruction laden streams.
While I admit to possessing more rods than brains and I would never want to deny anyone the pleasure & enjoyment of buying a new rod, try what you got FIRST to see if it is inadequate for the job before ascribing to a tackle formula for blue line fishing.