The very basic Vegas Pro is the same no matter whether you purchase Pro Edit, Pro, Suite, Post or 365 - the only difference relates to the add ons and extras (exception: 365 only allows installation on 1 device whereas the others allow 2 installations). I'm sure someone will correct me if I am wrong on this point.
Post adds some extras including better compositing features sourced from FXHome.
Effectively, the basic Vegas Pro 17 you get in Post is the same basic Vegas Pro that you get in any other VP package,
@star_wyvern … That's good news. With add-ons in Vegas Pro like BorixFX plugins, it's important to be aware that those add-ons may not work in later releases of VP (e.g. VP 18) because those add-ons are usually 'license locked' to the VP version that you bought with that/those add-ons. Though adding to the overall expense, consider buying BCC OFX or specific BCC Units directly from BorisFX to increase the chance of compatibility with later versions of VP as well as some other NLEs like DaVinci Resolve.