Pressed lugs can be as tight/short to the tubes' junction as you can make them with no differences in total joint strength as the vast majority of the joint's strength comes from the tube to tube contact and the filler's flowing between this. As to the "softer" steel's hardening from heat cycles. I hope your heat control and the cooling off rate is up to the task as the tubing will go through whatever cycles that the lugs see too. Remember that far more pressed lug frames have been used for many more miles that any cast lug bike has. Andy.