Hi Hako,
Thank you for the photo of the bench you work on. I for one like to see where the members do their carving work. Is it an old treadle sewing machine table? We have one in our family, still with the machine and sewing paraphernalia in its drawers that belonged to our grandmother on our mother's side.
The grill over box idea looks like a unique and useful solution. One could also connect an adjustable fan/vacuum/dustcatcher connection to that catch box for when sanding dusts are present.
A recent addition to my carving bench and work bench was a packet of four
"Bench Cookies". They are about the size of a hockey puck with non-skid foam rubber pads on top and bottom. I stack them to hold the dust catcher tube, higher or lower, according to the need. Sometimes one or two braces my hand or is used for resting the carving upon. They are proving to be very useful, but I use the carving peg and white malleable tacky pad the most. I have yet to try the "nupsi" style tool.
Janel