Here is my take on this.
The injection is simply there to keep the two halves together at the
correct length so that the column can be assembled. Once installed in the car,
the shaft has no where to go. The top part of the shaft is held by a C clip in the top collar.
The bottom shaft is held in the coupler by the blocks and a small pin in the block.
In an accident the injection plays no role. If the accident is major enough to compress the column,
then simply using glue will do the job.
Jules