Kanda AVR Handheld programmers have been popular for the last 20 years and are constantly being improved. They have always supported ISP and JTAG on ATxmega and ATtiny and in the last few years we have added both ATxmega JTAG and PDI interfaces.
Now we have added a TPI interface to support newer ATtiny devices. We are currently adding UPDI interface for the other new ATtiny chips. Are these popular chips and what is the preferred ISP connector for them, 6-way 3x 2 header?