It seems like all expander cycle engines currently in operation or in development use liquid hydrogen as fuel. The answer to this question indicates that RP1 won't work for EC engines because of its poor heat transfer properties.
I'm wondering if the same applies to cryogenic hydrocarbon fuels such as methane or propane. Intuitively, it seems like they should work fine. Also, the paper linked in this answer seems to indicate the oxygen can be used to drive pumps in a dual expander cycle - so, I'm guessing methane and propane can as well.
So, the question: are there any reasons for why methane or propane are a not a good idea to use in an EC engine?