ozbugz on "Are they back or should I stop worrying? [expert ID needed]"

Hi again,
Like others I was starting to think I was free then noticed something of concern that might mean 'They're baaaaaack.'
I would greatly appreciate opinions as to whether I need to get further treatment or should relax for now and continue to monitor.
A month or two ago I painted my bed slats with sealer and gloss paint. I have a passive monitor on the top slat (partially unpainted). Some had what could have been fecal marks on them.
The slats are not attached to the bed but rest on the black metal L shaped sides. The bed posts are wood with black metal arches linking across at head and foot.
I recently replaced my old torn mattress (encased) with a good one new encasement.
Some of the paint has worn off some bed slats at the point where it meets the bed sides.
I cannot tell if the black marks are fecal stains, new or old.
I have not had any signs whatsoever on passive monitor on top slat. But getting the odd bite (arm, calf). I notice them when they appear but they are not generally itchy (I previousky seemingly did not react much when I had original infestation - only twigged when I saw one).
Also the odd black speck on sheets and one blood spot.
I would be so grateful for advice from the experts and others here! I can't tell you how much I value this site.
Here are the slats:
https://www.flickr.com/gp/136704932@N03/Tsm7UL
https://www.flickr.com/gp/136704932@N03/3Hf56L
Also this was inside my pillow case today
https://www.flickr.com/gp/136704932@N03/gm8CSG
And this was on my bed yesterday
https://www.flickr.com/gp/136704932@N03/Vmm641