What printer for bw high-speed printing with CISS that does not violate the warranty, advise?

Question

Seal

Good day to all.
Please advise a printer with a native CISS, color, but priority for high-speed bw printing. I know that Epson has native CISS. Other manufacturers lose their warranty when installing CISS.
The problem is that from experience I can say that the print speed declared by the manufacturer often differs from the actual speed. As a result, you need to overclock, configure the printer a lot, etc. in order to achieve a result. Or can you tell me the manufacturer, whose maximum declared speed of bw printing corresponds to the figures provided, without dancing with a tambourine?
Thanks to all!

Answer 1

I look towards HP Enterprise 600, who will tell what?

Answer 2

HP LaserJet Pro 400 M401: 33ppm
280X
cartridge at 6900 pages

Answer 3

Take a look at Ricoh printers