for 2nd i2c display I hacked the oled node to take a Bus number

[dlarue]

rPi OS now allows setting up i2c buses on other GPIO pins but the default node-red-contrib-oled didn't let you specify the I2C bus.
My forked version lets you set the Bus number in the config node - https://github.com/dlarue/node-red-contrib-oled

I added the 2nd I2C bus adding this line to /boot/config.txt:
dtoverlay=i2c-gpio,bus=4,i2c_gpio_delay_us=1,i2c_gpio_sda=23,i2c_gpio_scl=24

Too bad there's so poor support for 128x128 i2c displays but 128x64 are cheap too.