For the Murano, I'm using the Apollo 2.0 with a 100mm(?) xBa LED behind it. It's like the shrouds were made to fit specifically the Murano's, they literally would not need any way of securing them if I didn't want to as they push on perfectly and stay stationary.
And for the RX's, I decided to use an Apollo 1.0 with NO xBa. I wanted to keep some sort of uniformity when I was choosing the shrouds for them.