Take this with a pinch of salt but I don't think that it's really the elision of one of the two k sounds that's going to mess perception up. "thing" vs. "think" + [kVmIN] "coming" does have a pronunciation difference: "think" undergoes vowel clipping and is perceptually shorter. It's how generally, Americans can tell the difference between "can" vs. "can't" even if the "t" is elided because the voiceless stops, in this case "t", clip/shorten the preceding vowel. In my accent, I don't have any kind of problem because the vowels in "can" and "can't" are different but in most accents (but not all) of American English, the two vowels are the same and the vowel clipping is how people don't confuse the two.

It's even more noticeable when it's a voiced vs. voiceless stop difference (eg. bad vs. bat but you can still hear it in baa vs. bat, in a standard American accent.)

Personally, I always thought it was more of a British English vs. American English problem. Most British influenced dialect speakers I know use "think" and most American English speakers I know use "thing"; generally, Americans don't use "think" as a noun and the word "thing" has a wider range of meanings. I see it used a lot to reference a certain grouping of materials, like "a thing of candy" which is a usage that you don't really find in Britain. I always thought that in that context, "thing" took the meaning of the if- whole clause, like "that".