You agreed that during remaining in rigpa one still hears noises, etc. and said that they are karmic products.
Yes this is correct, but the sensory perceptions you have while being in the state of Rigpa are not dualistically grasped by the mind, because you are functioning in the mode of Rigpa, riding the wisdom wind.
At the same time, when remaining in rigpa, one has thogal visions,
Not necessarily, if the key-points are not applied, you remain only in one side of rigpa.
and they are wisdom products.
Please don't reformulate wrongly: I said that visions are the dynamism of Rigpa. It is of no use to reformulate things in a different mode, this will only lead you astray. Try to jump over the vocabulary that may block your understanding right now and get the meaning in the terms of Dzogchen only.
Only sems has karmic products and only rigpa has wisdom products.
Formulate things like this: sems is characterized by dualistic grasing ; Rigpa is characterized as being beyond that, being nothing else but the direct knowledge of the natural state (for one part of its definition).
Are sems and rigpa present at the same time?
No because sems is functionning in the mode of marigpa and Sems-nyid is functioning in the mode of rigpa.
Can one be attached and non-attached concurrently?
You still have not gotten the meaning of these modes (tshul) of rigpa and marigpa.
Because if yes, buddhas can still be afflicted. So that's why I don't really see how what you say is possible at all.
It is because you need to get the DI in an experiential mode (not that of Trekchö but that of the 21 DIs of Thogel). The explanation of the visions of thogel deeply depends upon the visionary anatomy of the body, which is quite unique to Dzogchen (although based on medical treatises for one part). I can't enter the details here because this is not the place to do so, but you have one channel connecting the heart to the eyes. This explains how Thogel visions arise. At the same time, that channel has branches which open in the sense organs, which means that the organs are functioning (you still see objects, hear sounds, etc.) but you are not perceiving them in the state of the mind: you perceive them in the state of Rigpa. The difference is also valid in terms of Trekchö (the details of which, with the re-arising of thoughts after remaing in Rigpa, are explained by Peltrul Rinpoche in his Glorious King text).