How far can I go witha Meiser"Combo"?

That`s my new mission maybe.
I have Bob Meiser`s "Troutmaster Combo"
which is a 9`3"6 wt. single handed rod that converts
toa 12`6" Spey 5-6 wt.
So,what happens if I attept to use this common butt...
[there are 5 pieces-the Spey 4,ther single uses 3,they share the butt]
for 4 wt.?
Will this butt be to heavy?
Is this a deal breaker?
What do you think?
Most of us with Meiser rods would say that Mr. Meiser knows what he is doing.

Damn straight he does.He invented the switch for crying out loud.
I have built on three of his blanks so far.

The thing is,I have already pestered him too much.
I`m thinking out lous herre..[I`m in the right place,correct?]
and thinking this out a bit before I ask foir more of the man`s time.