They have the pocket, but the small opening at the bottom is too small for a big kneepad, and I've started using the radbacks ones (which are great btw), but it'd be a faff getting them in and out. On other pairs I've undone some stitching to make the hole bigger, but it's still not as good as a proper pocket. I'm assuming you're talking about ones that look like this:
I’ve got them too, I have wondered about opening them up and putting some knee pads in them. Mine certainly don’t look like that though they are very painty now
They have the pocket, but the small opening at the bottom is too small for a big kneepad, and I've started using the radbacks ones (which are great btw), but it'd be a faff getting them in and out. On other pairs I've undone some stitching to make the hole bigger, but it's still not as good as a proper pocket. I'm assuming you're talking about ones that look like this: