I just got an ism prologue saddle but I can't for the life of me find a good seating position.

If I sit in the front-middle of the saddle, kind of where the cutout starts, my butt feels good like all the weight is distributed where it should be. However, I feel like the prongs stick out too far and rub up against the inside of my legs. This is less than the ism road which I tried earlier.

I also tried sitting really far forward on the prongs, like where as one person describes it as "If I sit 1 cm farther forward, I'll fall off". No prongs rubbing against my leg but the position is really uncomfortable. It basically feels like all the weight is put on these points right between where my butt muscle ends and my thigh muscle starts. Plus I feel like the prongs are far more narrower than my actual sit bones. I have a brooks saddle and the indentations are about 3.75" apart but the prongs on the prologue are only a couple of inches apart. Not to mention if I sit this far forward, I basically need to put the saddle almost a whole saddle length farther back than my previous saddle and none of fit pictures demonstrate this.

Where are exactly should you sit for the ism prologue? I feel like sitting in the front-middle of the saddle feels better but am worried about chafing. I do have big thighs so maybe this saddle just won't work for me?

I'm a guy (I hear more women like ism because of wider hips) and bike in a road position on my hoods. I tried to put myself in a more "proper" biking position by sticking my butt further back and straighting my back but this still doesn't feel like I'm putting the weight on the correct place.