The paladin would need to fully exhaust his Lay on Hands ability for the day to take full advantage of it. The way I see it you keep track of total usage of Lay on Hands and compare it to whatever the current CHA bonus dictates as a maximum. You can get extra use of Lay on Hands while Eagle's Splendor is in effect, but you can't repeatedly cast the spell to get you 2x(Paladin Level) hp usage of Lay on Hands each time you cast the spell. It's analogous to the way CON bonuses effect hp, compared to how temporary hp work.
- Paul San Clemente