Flying a P56 will actually make you a better pilot, most pilots that have only flown a PA28 or a 172 probably don't even know what coordinated flight means, peoples with P56 or glider background know it petty well. It won't make a huge difference on a daily base, but as a flight Instructor I can tell you that learning on a tailwheel plane is good for other future tasks, like flying a multi with a failed engine, probably 90% of the 152-172 trained only will have an hard time learning how to keep coordination during VMC, while for a tailwheel pilot it will be more natural. other good transfer of knowledge is precision during landings, most tailwheel landings are done engine idle so you will develop a better sense for change in glide, this will be really helpful when you start flying heavier planes. The downside of training on a P56 is that you won't develop other skills and you will be really limited in learning navigation techniques (most pilots in Brazil learn how to use a VOR when they start IFR). The best compromise is do have side programs, like an UTR or something where you can develop your stick skills.
I agree on the instructors most i flew with, showed up late and did not cared too much about the flight.
Unfortunately the Macho culture and the lack of Crew Coordination is deep in the Brazilian aviation culture, just look at the fact that even in civil life Captains are called Comandante. This guy I contacted for regulation classes made it a big deal to be called comandante, when I go to get classes he shows up in a Barcelona soccer jersey, shorts and flip flops,....professionalism????????