Plotting, (EDIT: removed line of code that wasn't doing anything )
Manipulate[
Legended[
Show[
lpp3d,
Graphics3D[
Table[
Flatten[
{If[MemberQ[selection, n],
{EdgeForm[Thick], Lighter[Red, 0.25]},
Nothing],
Polygon[vertices[[faces[[n]]]]]}],
{n, Range[Length[faces]]}],
MapIndexed[Text[#2[[1]], #1] &, vertices]]]],
AxesLabel -> {x, y, z},
BoxRatios -> Automatic,
ImageSize -> Medium],
PointLegend[
ColorData[97] /@ rlGV, rlGV,
LegendLabel -> "Group"]],
Row[{
Control[{{selection, {1}, "highlight face"},
Range[Length[faces]],
ControlType -> TogglerBar}],
Spacer[40],
Button[Style["Clear All", 10], selection = {}]}],
SynchronousUpdating -> False,
TrackedSymbols :> {selection}]