It is clearly racist. "Ricing" comes from a derogatory term for Asian racing vehicles. You cannot excuse the racism inherent to it by personal ignorance. It's the same logic as black face being racist, whether you're personally aware of the history behind it or not.
Though I no longer live in the US, as an Asian computer scientist, I am quite aware of how it is clearly perceived as a racist term by many Asian Americans. To me, it will also never stop being offensive. So, please, stop with this "ricing" stuff.
The term "rice burner" originated in the Anglo-American context, and the word "ricing" cannot be divorced from the way people use "rice" as a versatile and generic racial epithet in varied context outside of the software world. As in people going, "haha, rice" something when being racist against Asians. It's a long and ignominious American tradition to demean racial minorities with food. As in insulting Mexicans with "bean". Anecdotally, some older Italians still remember being made to feel bad for eating pasta, when Italians weren't white yet. The term "ricing" will certainly remain racist due to the way anti-Asian racism continues to work. Hence my point that the term must be abandoned, if one wishes to not be racist. Just find a different word for it. it ain't that hard. It is certainly not possible to use an American word with racist origins without divorcing it from the cultural context from which it came.