You have to remember when breeding that there is a very serious genetic hoof flaw that only expresses in ponies that are homozygous for it. It’s a recessive. However, a heterozygous pony WILL BE A CARRIER, and there is a 50-50 chance that the “bad” gene will be found in each foal. Breeding to a TB will almost certainly mean that the resulting foal will not express the disease, but then there is still a chance that the foal will be a carrier and, if bred to other than a Connemara, could pass on the gene into the wider horse population.
With these known genetic diseases that are limited to one breed, it seems to me VERY important to understand the genetic consequences of breeding to carriers; and, it also seems to me, that the responsible thing is not to breed to a carrier unless the resulting foals are tested for the disease and never bred if a carrier. Males can be gelded, but fillies must be in a situation where there is no chance they will ever be bred.
The Connemara breeding societies worldwide are very aware of the genetic flaw and have been proactive in their response to it, unlike the AQHA and HYYP. If you are planning on a Connemara breeding, please get in touch with the
American Connemare breed society and discuss the disease, its prevalence, and whether the stallion you are considering is a carrier.
https://en.wikipedia.org/wiki/Hoof_wall_separation_disease
Off my soapbox now.