i agree with caddie betting 7.5 > betting 6...also i would assume random regs are going to be calling much wider than that preflop, i would def include suited connectors, and some regs will still call with KQo/KJo/ATo and the like, you raised in EP, implieds are usually higher here. IDK i just think you are going to be costing yourself a lot of money just assuming that a ton of hands aren't in his range, especially when as you said there was a whale in the SB, why wouldnt he want to play IP vs a fish with a high implied hand (not that KQo/KJo/ATo are high implied odds hands but the suited connectors and suited aces surely are)?

sorry if this made no sense im blazed right now