I personally prefer to wear the Retainer Band at the base rather than behind the glans. This helps to maintain a larger flaccid for great size and subsequently more secure fit of the silicone ring behind the glans. The glans will also be somewhat larger but there are many variables at play so it is important to become more attuned to the fluctuations and augment in ways that work most effectively for you. However, a fit that is too tight would not require layering of the spandex sleeves or use of the Retainer Band.
I like to wear the Sabre Skin for the greater level engorgement. However, you need to recognize when the glans becomes too large and purple but at this point it is fairly obvious that some adjustment is required for a looser fit.
Experiment to understand the variety of possible set-ups and the parameters of optimization which meet your needs.