Two thoughts... neither of them directly related to the capabilities of
the 410c I2C controller (I'm afraid I don't have any I2C peripherals
that perform clock stretching).
Firstly, the FX2 based controllers that work with sigrok are awesome
for double checking assumptions and things like that. They are widely
available on eBay and can be got very cheaply. Search for "USB 24MHz
logic analyzer". Ignore any software that is bundled with it, sigrok
provides a complete software stack for these devices, including firmware.
Secondly, if you cannot get the hardware controller to work then
switching a bitbang driver such as i2c-gpio.c (CONFIG_I2C_GPIO) might
allow you to work around things in the short term. See
for some clues on how to configure this within device tree.