This may cause them to re-examine how they do the entertainment, but as it is now, that would require hiring someone and paying them to stay at home and not audition for any other jobs on the off-chance that an injury happens.
Given that this is part of a duo, currently to hire someone they would either have to take the other performer away to ensure that the chemistry is there or hire TWO new performers and put the uninjured one out of a job.
AMEN! It's not like it's Elsa in Frozen, Rapunzel in Tangled, etc.