I think it's pretty common with most zirconia. I haven't used Lava + . Saying that, the mass of the pontic doesn't let the pre sinter stain to penetrate as deep.
When it's just the crown it's usually a thickness from .5mm to 2mm. The pontic is thicker than the abutments.
It takes some more brush strokes on the pontic to get the shade a bit more uniform.
I switched and prefer preshaded zirconia now. But I totally get the pre-sinter stain for more control of shade. I use it for incisal areas.
