assuming peter's suit in homecoming is the same suit he wore in berlin, while it's totally plausible that tony built that whole suit in a day out of like, scraps he had planned for nat or hawkeye maybe (hence instant-kill mode?), it is p clear tony has been tracking peter for awhile - he has his //home address// - and tbh probably having friday keep other parties off peter's trail, which suggests he's been working on that suit for awhile as well and we know in infinity war he has a full nanotech upgrade that is, probably specifically coded to peter, ready to go whenever. and while optically it may be the same iron spider suit he unveils at the end of homecoming, i really doubt he prototyped that tech for the kid before using it to upgrade himself, so the infinity war iron spider suit is prolly like, spider-man mark iii, at least which suggests he just, builds suits for other people now instead of iron man variants like he has a hulkbuster for banner in the garage, there's probably a whole wing of suits on ready at avengers hq that steve thor and rabbit will find in iw2, there's probably like a car for rhodey that turns into a tank and a black and white hulkbuster