I saw that thread on the $140 conversion cylinder and read it with interest. And I agree, for the money, I too would just get a purpose-built 45LC.
I was unaware of the heat-treating issue surrounding BP guns..but I will truthfully fall into that demographic (probably) of playing with BP as an avocation and an aside to my cartridge toys.
I won't be building out the kits...I will play with what is commercially available. BP is about the process and the history. But I LIKE electric starters on cars...I have no interest in returning to cranking a car by hand. Technology has moved on. Smokeless powder cartridges have definite advantages which I for one enjoy.
BP is a trip, but I need to have the time to properly futz with it.