Lay on Hand heals based on Charisma Modifier x (Paladin+Divine Champion)Level = Maximum Heal/Damage result, with a cooldown of a literally long ten-minute. Also an interesting fact.
When Warlocks' beams got disconnected from the weapon so that they can no longer benefit these delicious, juicy Champion Dart that gives a massive boot to their AB. So does the same happened for Paladins/Divine Champion's Lay on Hand. It no longer benefited from the extra AB that paladin get from wielding their weapon, but instead ignored weapon's added AB effect.
Now, back to Laying on Hand. It was introduced three years ago, technically approaching the fourth year in October 2017 update.
18 days later, at the time, Yellowscateye was new coder, but he introduced complete fancy rework for the Knight Class. And gave them a far better healing utility called Final Stand.
Final Stand is level 5 Knight ability that gives you 1d8 HP heal per knight level, then additional 1d8 heal for every 5% of the party member's health is missing. And if the player in question is a ward, they get an additional 50% healing from your Final Stand. And of course, if you took Valiant Path. You get a 10 rounds duration of 10 HP regen.
At cooldown of three minutes.
Hey. That's pretty good.
Yeah. Like the chances of party member's health being low enough that you can heal them at maximum of 232 (or 348 if ward) in question are pretty low. And then there's dice of d8.
Paladins/Divine champions' on other hand are flat value. If you're a level 30 paladin with 16 Charisma, and you somehow gear up enough. You're only looking at like 270 heal every ten minutes. Compared to a Knight that can do about three more, and can be done to entire party in that entire 10 minute window.
The justification I can find for why Lay on Hand is ten minute cooldown, is it's a massive damage to undead.
Remember. Warlocks got their inficast beam AB disconnected from their weapon, ending era of champion darts. And when that happened, that also applied to paladins.

This is with just normal setup, no zoo/divine favor/Prayer applied onto me. No blessed weapon either.
Then I decided to do it again, but with zoo, divine favor, prayer, and blessed weapon.

And answers I got was that only zoo, divine favor, and prayer affects my AB for Layer on Hand inflicting damage on undead. Bless weapon did not. (Know that I have additional +5 AB with blessed weapon, and Weapon focus feat)
Currently, Paladins/Divine Champions need a better tweaking for Their Lay on Hand CD. And also, I firmly believe Lay on Hand's damage on undead should really be halved.
What you guys think so far? inb4 Anti-paladin brigades