you could override the default popup sass.
something like this is what i have used.
just add a YOURCUSTOMCLASS to a popup layout (not modal poup)
and this sass:
.modal-dialog.mx-window{
&.YOURCUSTOMCLASS{
top: 60px !important;
right: 0px !important;
left: 50% !important;
width: 50% !important;
height: calc(100% - 60px) !important;
//background-color: red;
&.right{}
//remove styling
.modal-header.mx-window-header{
display: none;
}
.modal-content{
border: none;
border-radius: 0;
box-shadow: none;
height: 100%;
// background-color: red;
.modal-body.mx-window-body{
//background-color: green;
overflow-y: scroll;
height: 100%;
}
}
}
}