Initial state options for Viterbi algorithm

When instantiating a Viterbi decoding block, there are options to
what the initial and final states should be or that they are unknown.
poses no problems if the FEC encoder is initialized similarly for each
block of data. However, when multiple blocks of data are encoded without
resetting the encoder to the same initial state each time, but instead
encoder remains in the previous final state, there appears to be no
to set the Viterbi decoder initial state to its previous final state. As
this effectively increases the block size, and therefore improves
performance, it seems that this would be a desirable feature. Are there
plans to add such a feature or are there other drawbacks that I may not
aware of?