Change the i2c bus clock speed to 100kHz and keep this configuration

Hi, 

I am working on a project using a LattePanda Mu with custom carrier board and Ubuntu 24.04. Some i2c sensors I use at 1.8V are not compatible with the i2c highspeed mode (400kHz) and thus I am looking for a way to set the i2c bus clock to 100kHz. I couldn't find any way to access this setting from linux, is there another way to do that ?

Furthermore, I would like this setting to persist and I want to avoid the BIOS coin battery (I don't want to lose i2c sensors when the battery dies). I have seen in the support section that it is possible to load a new bios from USB, is it also possible to save the bios with its current settings to USB, or any other way (custom bios, using external programming tool)?
 

Thanks in advance

Emmanuel