https://rpgbot.net/dnd5/characters/oversized-weapons/ https://tabletopbuilds.com/oversized-weapons/ https://www.dndbeyond.com/forums/dungeons-dragons-discussion/rules-game-mechanics/30667-oversized-weapons-used-by-player-characters-with https://www.reddit.com/r/DnD/comments/tf79p8/have_anyone_ever_rule_a_player_using_oversized/ https://www.reddit.com/r/dndnext/comments/nv8b4t/do_you_ever_use_oversized_weapons/ https://www.reddit.com/r/DnD/comments/40jzfb/5e_oversized_weapons_for_pcs/ https://blackcitadelrpg.com/oversized-weapons-5e/ https://www.reddit.com/r/dndnext/comments/32j53o/large_size_weapon_stats/

It's not as much as an angleshot as it is making sure the DM plays along -- probably more similar to how Wild Magic works.

So what I like about this tangent/design is that you're basically giving yourself disadvantage to guarantee a critical hit... and it avoids the feat tax that comes along with Great Weapon Master because it performs slightly worse than GWM in most cases but when you have the correct setup, it does better.

How does Enlarge/Reduce work?

Enlarge/Reduce
Enlarge. The target's size doubles in all dimensions, and its weight is multiplied by eight. This growth increases its size by one category - from Medium to Large, for example. If there isn't enough room for the target to double its size, the creature or object attains the maximum possible size in the space available. Until the spell ends, the target also has advantage on Strength checks and Strength Saving Throws. The target's Weapons also grow to match its new size. While these Weapons are enlarged, the target's Attack with them deal 1d4 extra damage.

https://www.reddit.com/r/dndnext/comments/dmyc5y/why_doesnt_enlarge_grants_one_extra_damage_die/

Let's talk about how advantage and disadvantage work...

I occasionally rant about "the presence of advantage/disadvantage" and how it doesn't matter the number of sources of advantage or disadvantage you have... if you have advantage and disadvantage, they cancel out the extra dice roll but you still simultaneously have advantage and disadvantage for the purpose of spells/effects/traits that may apply.