Update, photos taken yesterday:
I drilled out the two suckers, after which another immediately appeared:
Left Little Prince was sprayed multiple times with 10 ppm Thidizuron (TDZ):
Compare with same plant, lower left, on 2/22/17:
Growth seems to have improved slightly with TDZ treatment.
Similar treatment seemed to suppress sucker growth on a larger Little Prince:

But, did not improve growth of mother plant.
So, starting yesterday, I will spray the GA treated Truly Tiny with 10 ppm TDZ, hopefully to suppress sucker growth.