RE: Felt clunks
I have had one experience of fibres from a felt filter partially clogging my Walbro carb fuel screen. The symptoms was that the engine would start normally but would not run above a fast idle.
That Festo filter looks like a good thing to have, but now I simply do a seasonal check of the screens for any debris, plus the fact that the felt filters do such a good job of filtering I still use them.
Karol