wits end upgrade idea (only affects minions)

I was curious if wits end would see more play on heroes like Shen and others if it offered a way to help a little more with wave clear. So idea is you pay ~300 gold to upgrade wits end It then gives you spellblade every 2 sec (kind of like the new Stormrazor mechanic) (200%base ad) but only vs non champion units/or just lane minions. or instead of Spellblade it could deal a flat value say 60+4 per level Magic Damage, that way heroes with low base AD can still benefit from it equally.

This could allow a tankier bruiser build on Irelia and she could still reset Q against minions. Maybe the cooldown can be triggered when hitting enemy champions too but not apply damage. otherwise it might be too good for q resets vs minions? Not sure. It could give Irelia slightly different playstyle. https://imgur.com/Y3jAlJT

EDIT: cost of item and gold refund is open to change of course as well as other stats. I think the gold refund could be 400g over 8 or 9 mins. also should read basic attack deals bonus physical damage equal to... not apply a spellblade like I wrote. It doesn't have to deal 200% either could do 180% base AD

Another thing I wanted to look into is to remove the very niche quality of Wits End that by reducing a heroes MR, it consequently reduces any of their abilities that scale with MR (correct?). I don't think this should be a thing. By removing this it could allow the item to receive slight base stat buffs. Example: perhaps the on hit dmg could increase against targets with more MR?

reducing the MR to all enemies is a satisfactory enough debuff IMO and I'd rather the item not be too debuff oriented, so as to be less situational.

Also the M.R. debuff could also not affect any keystones that increase MR scaling / factor the flat mr reduction after.

all in all I think this would give the item a greater sense of belonging. and be fun as well, as the wave clear adds a mini game to last hitting.

Edit: added a few key points in this comment below: https://boards.na.leagueoflegends.com/en/c/gameplay-balance/TnMguz23-wits-end-upgrade-idea-only-affects-minions?comment=0002