In the Tyros 4 they introduced a function, where I can change the drumkit, exchanging congas by bongos or mix my own kit from different kits.
I found this function in PSR S 970, the only difference, the new kit will not be stored as custom voice kit, but in the style file.
Today I visited a Tyros 5 owner, tried to show him this function - and it doesn't exist. Introduced in Tyros 4, skipped in Tyros 5, continued in Genos.
Good to know, that Yamaha loves us, what would be, when they would begin to hate us.