Ikelite lens ports

I know the question of glass vs acrylic has been asked a few thousand times but all of the searches seem to apply only to dome ports. Does this also apply to the flat ports since the area is much smaller and the cost is considerable cheaper? What do you use (glass or acrylic) and why? Ikelite points out weight on their port finder website but I can't imagine there would be much difference in the flat ports but I could be wrong.

Have and do use flat port when using my macrp lense with no issues for years.