@protoss71 My understanding is that they had a few of the front ported Encore frames already built and I imagine they wanted to use them, but still offer the new non front-ported sound, hence the foam plugs. If they are removable that gives you some options to at least play with porting and unporting them to see which you prefer.
Regarding the upper quad resistor posts, I asked Eric about them. He said if you use some resistors you basically can turn down the tweeter. He said with such expensive speakers if people wanted a tweak, installing those resistors allowed him to offer some tweaks from a distance. If you feel it is too bright and want to turn down the tweeter, you would need to reach out to them to send you some resistors. I haven’t heard of anyone yet using them. But you never know, you might have a super bright amp or room or something.
Out of general curiosity though, I wonder why the Encores have four resistor posts each, while it looks like the Ulfberhts only have two.