I2S Peripheral in parallel mode (or RMT?) to send data to multiple (bitbang) SPI DACs

[sysobln]

I'm working on a project where besides a I2S audio DAC on I2S0, I will need to update (using I2S1) 4 or more 2-ch MCP4822 DACs with DC outputs at audio rate and all in-sync from an ISR filling in the data.

I've seen hacks using the I2S parallel mode to shift out data and bit-bang various protocol,
so I'm trying to figure out if it's possible and how to best achieve it.

What would be the best (and hopefully easy) approach?