An enchantment for swords that speeds up attack speed, but with drawbacks

Many people, myself included, prefer the feeling of using swords in versions of Minecraft prior to 1.9.  What I am suggesting is not a simple toggle to the legacy combat mechanics.  I would add an enchantment that, when applied to a sword, effectively removes the cooldown added in 1.9, potentially with a limiter on how fast the sword can be swung, such as the system that currently exists in the Bedrock Edition.

However, this would not make a sword with the enchantment overpowered compared to a normal one, as there would be negative effects when using it.  If a sword with this enchantment were to be equipped by the player, the off-hand slot would be disabled.  This would prevent the player from using a shield, which would pose a disadvantage in both PvE and PvP combat, since the player would have decreased protection from melee attacks, projectiles, and explosions.  In addition, the damage per strike would be reduced to match the previous tier of sword.  Iron swords would do the same damage as stone swords etc. 

This creates a sword that is not objectively better than a stock sword while at the same time making people who prefer old combat more comfortable with wielding the sword.  I believe that this is an ideal solution for accommodating veteran players and server owners, while avoiding a massive rollback of features or a toggle, which the developers will not add.