I am studying emerging Brazilian Portuguese consonant clusters and I'm unaware of how to properly call a group of positions such as "word-initial" or "word-final position". The aim is to use this term as an explanatory variable. I've thought about "segmental position" or "grammatical environment" but I'm still unsure about their appropriateness.
Late answer but I hope it helps.
For positions within a syllable, you may want to use "prevocalic" for describing /p/ in pat and "postvocalic" for describing /t/ in pat.
Though when it comes to deletion processes, there are some well established terms such as:
apocope: describes the deletion of the final phoneme in a word. aphaeresis: describes the deletion of the initial phoneme in a word. syncope: describes the deletion of the phoneme in word-medial position.