OK you didn't mention you were having sheet vinyl pro installed, DIYers on here (like me) use the piece goods like LVP. The slide is designed to seal against the wall when fully opened or fully closed. You have some adjustment room, but dropping it down an inch will likely create some sealing issues at the top. Carpet is typically used by the slide so there's a flap to cover that gap, and also because the slide needs something to ride on besides the rollers as it comes it. Sheet vinyl is pretty thin and it won't take much for the slide to catch the edge and either scratch it or tear it as it comes in.
Maybe post a pic or 2 of what you're talking about and lets go from there. Seems like every mfr builds their slides a little differently.