Steve and tried one of those magic ladders last year when we went to Virginia Beach to work with the SEAL teams. Man can you get tired fast on those things. But you can say that about any piece of exercise equipment.
If you are stuck trainning indoors a lot then yes mix up some of your aerobic works with this ladder thingy (it seems like fancy Versaclimber). Being quadrupedal its going to place a much bigger demand on the heart to supply blood for all for limbs. This is good as that’s what class 3 and 4 climbing in the mountains does too. But I’d start with Z1-2 workouts in your base period. Later it cold be used for ME workouts too.
Keep in mind though that like all these gym machines, you don’t actually have to lift body weight vertically. Your body stays put and the machine moves under you. So the strength effect is quite different than actually climbing uphill with a heavy pack. This does not mean the Ladder is ineffective but I wouldn’t rely on it 100% for ME unless that was all I had.
Have fun with your new toy.