Those shots were made with the factory stock trigger. If you’re that sure it would help, I’ll have to try the Volquartzen kit.
Measure the trigger pull and if it's more than several pounds, reduction down to 2.5 lbs should help reduce group size by not extrapolating input on trigger to move muzzle.
Have you, or anyone, heard of tuning the stock screw and barrel band screw for better accuracy?
My previous 10/22s had barrel bands and my Collector #3 did not come with barrel band (Like LVT model). Having done testing with barrel band and without, Collector #3 free-floating the barrel and without, there's mixed report of accuracy improving. I think this maybe due to barrel band acting to limit barrel vibration/harmonics to reduce muzzle whip in producing smaller groups but this may be specific to ammunition causing different levels of barrel vibration.
When I did free-floating of barrel to freely slide a sheet of copy paper around the barrel, initially I got mixed results because I used various brands of ammunition (Likely producing different barrel harmonics/vibration) along with shim used to free-float the barrel allowed the trigger to move the rear of receiver in the stock. I addressed this play by initially modifying the shim then later adding strips of electrical tape to rear of receiver to secure it from moving (Yes I know, not a proper "bedding" practice but this was done for "real world" challenge meant for casual "plinkers", not match shooters).
So if you are considering removing the barrel band and free-floating the barrel,
I would recommend you take steps to "bed" the receiver or secure the rear of receiver so trigger input does not use the action bolt as fulcrum to move the muzzle. Once you secured the receiver to stock to eliminate muzzle movement, you then can test action bolt tension.
As I found out during my 10,000+ round testing, it is best to only change one variable to see if you produce smaller groups or you will be pulling your hair out.
Ultimately, your goal is to secure the receiver to stock so trigger does not move the muzzle, especially if you are free-floating the barrel by removing the band. As many have found, if receiver is not "bedded" to stock, you may end up enlarging your group size over using the barrel band.
As to different action bolt tension producing smaller groups, I got mixed results likely from other contributing factors. Once rear of receiver was secured to stock and I was using ammunition 10/22 factory barrel liked (CCI SV/Aguila 40 gr LRN/CPRN), smaller groups were produced with action bolt with moderate to tighter tension (But not tight) than very light to light tension.
This video uses free-floated barrel 10/22 with different action bolt tension producing varying sizes of groups using CCI SV at 30 yards (Interestingly, my accurized 10/22 with Volquartsen kit and factory barrel free-floated now produces similar groups at 50 yards with CCI SV of 1/2"-3/4").