Whandall:
You should not place hardware related setup (like pinMode) in a constructor.
It could be run before the Arduino's init function, so it may not work.Such initializations belong to a function often called begin() called from setup,
which is guaranteed to be run after init.
While that's definitely true for UART and timer related initializations, all pinMode does is writing to the IO registers.
As long as you're not using an Arduino variant that does weird IO initialization before running, it should not be overridden, and it should work perfectly fine.