I merged my PC account as a primary with my old PS account, and my PC account was at max Riven capacity of 180 Rivens. My PS account had 84 Riven slots on it, which means I paid for 69 of them (over 1300 plat), and after the account merge I am still at 180 max capacity. The Rivens transferred, but not slots, so essentially the account merge caused the evaporation of a large amount of plat into thin air, from the console which had no coupons for plat price. Nothing in the Merge FAQ stated this would happen. I am not sure what I expected, but it is a little hard to swallow that 1300+ plat was basically thrown in the garbage.