of which HE? what is the HE on your app?
The House Edge of my app is 0.5% and I pay out 50% or 75% of that what I receive, which is 0.25% of that what you wager.
So your title is misleading: it's not 75% of the house edge but rather up to 37.5% of the house edge.
Since you receive half of the house edge for the wager and are willing to pay out a maximum of 75% of what you receive, that is equivalent to 37.5% of the house edge.