Sad news actually, could be due to low contrast sky.
I tried to use the red filters which I ordered for my Ranger and my Borg 45ED II as Cheapy-ERF but they show nothing. The solar disc can reach focus, but none of the H-alpha features could be detected.
I immediately suspect that the etalon module was over heated and thus enlarged the bandwidth excessively, but then on removing the module, I found it very cold, not even warm since it's not in the focal plane indeed.
Later observation with my Solarmax 40 told me that, the contrast of today's sky is very poor indeed, rendering nearly no prominence visible, and surface detail has very low contrast. Double stacking with the PST etalon module helped a bit, but still, it's way below what single Solarmax 40 will show normally.
So, the experiments are not failed, just could be due to poor sky, shall try again soon when the sky improves.