HowTo use UARTE 250000 8N2 plus TxBreak for DMX512 protocol

I'd like to use a nRF52840's UARTE0 as interface for a DMX512 controler.
For that I'd need to set the interface at 250000 baud with 8N2. But I can't see how to configure 2 stop bits via nrf_uarte_configure(). This function allows to control HWFC and parity but not the number of stop bits, why?
What can I use instead?

In addition the DMX512 protocol would require a break (~100µs LOW, ~12µs HIGH) as lead-in for the following data train (up to 513 bytes).