I have used those from that link. I told the seller to make a 50/50 of low and high density since he mentioned their difference and he agreed. Quite nice not to be worrying about foam size and proportion with that. It really adds new ways to tweak and play with filters.Yes, I am aware of your mod (especially for the A6). Although, I am pretty sure you used some DIY materials you made yourself, rather than the ones you can just buy and use at once.
These:
https://www.aliexpress.com/item/1005002711483821.html
Currently I'm putting 3 pieces of low density on LZ A7 Black and 1 high and 1 low on LZ A6 Black.