Since borrowing is primarily a phonological phenomenon, phonetic features will provide an indication of how typical (or atypical) pronunciation of the word in a language; loanwords are expected to be less typical than core vocabulary the language-pair and reduced only to a small set of plausible changes that the donor word can undergo in the process of assimilation in the recipient language.
the borrowing system only minimally overgenerates the set of output candidates given an input.