Okay, here's the setup - Oracle with the Lame curse, defined below, straight from the Piazo PRD:
"Lame: One of your legs is permanently wounded, reducing your base land speed by 10 feet if your base speed is 30 feet or more. If your base speed is less than 30 feet, your speed is reduced by 5 feet. Your speed is never reduced due to encumbrance. At 5th level, you are immune to the fatigued condition (but not exhaustion). At 10th level, your speed is never reduced by armor. At 15th level, you are immune to the exhausted condition."
The character has the Lore Mystery, with the Sidestep Secret revelation, again, defined below, straight from the Piazo PRD:
"Sidestep Secret (Su): Your innate understanding of the universe has granted you preternatural reflexes and the uncanny ability to step out of danger at the very last second. Add your Charisma modifier (instead of your Dexterity modifier) to your Armor Class and all Reflex saving throws. Your armor's maximum Dexterity bonus applies to your Charisma instead of your Dexterity."
I understand that your Charisma bonus applies specifically to your AC and Reflex save ONLY *instead* of your Dexterity and that your armor's max dex bonus applies to your charisma instead of your dex. I also understand that your speed is never reduced due to encumbrance.
Here's what I want to know: Would your encumbrance affect your AC and Reflex save if you were carrying enough weight to put you past your medium or heavy loads?
I personally would rule against the (cheesy) interpretation (it's my own character I'm building for PFS) and say encumbrance would effect your AC in this case, but I can see reasons it would not.
How would you interpret the RAW?