Is [tʃw] a valid pronunciation of the consonant blend 'tw'?

Solution 1:

How very interesting. The change of palatal glide [j] and [r] to an obstruent after a coronal obstruent is common in English ("want you", "tree"), and [u] has acquired a palatal articulation in earlier English ("value"), so for you, perhaps we can connect the dots. [w,u] become palatal, then after [t,d] the resulting palatal glide becomes an obstruent.