Ecom keyword tracking

I’m distilling a large keyword list for an ecom products list built over a period of time and from multiple tools. I’m considering which ones are worth tracking in ranking monitoring services. How do the experts here decide which keywords among product-name and long-tail variations of them to actively track over time for a good actionable “share of voice” report?

• Track all [product title] and [brand][product title] exact matches
• Filter out -s plural variations unless it shows more volume than singular. Does this actually matter? Or is google not that literal and generally considers these variations equivalent?
• Keep any kw with featured snippet presence
• Prioritize “[product] for sale”, “buy [product]”, [product] “in stock”? Track them at all? I understand this shows intent but I’m not sure if the variations are worth tracking individually, given “buy” “shop” “for sale” etc are all definitely included in various ways on product page metatags and content. The products are niche enough that searching for [product title] can fairly safely imply purchase intent

Any other considerations or tips to clean up the list and prioritize long term tracking candidates?