So I just recently got into Canon because of the 200-800 lens availability. Sometimes I need to hike to places where I want to shoot, and there is no reason to have the kit dangling when it is still dark and I'm not going to use it yet. I did not want to put much money into a backpack for possibly low usage, and there are actually not a lot of backpacks out there that will fit the R6 Mark II and RF 200-800 Lens, in fact I found none (I have since found that the Ruggard Alpine 600 should work). So I stated looking for large enough backpacks that were not expensive.I found an Adidas Backpack on clearance for $16. I had already decided that a dense exercise mat could provide the needed padding. and I found one for $13. I also got a bottle of vinyl glue for $5. Next step was actually build it. I wanted to be able to put the kit in from the top of the bag pointing down, preferably with the lens hood on. I knew that I did not want the lens hood to support the weight of the kit, so I decided the weight should be on the non removable tripod foot and a little on the front edge of the camera body. I Measured and cut the foam as I put it together. There is a piece of foam wrapped around the lens with a cutout for the tripod foot, the tripod foot then has another piece wrapped around it. Then there is another piece of foam going around the inside of the bag, which gives the bag some shape as well as an extra layer of protection, between the two main layers of foam, I stuck some other foam material in for stability and keeping shape. I have not actually used the bag in the field yet, just a little test at home. I will possibly add another piece of foam to the top.
Tom, adapting things to suit your photography needs is what makes what we do worth while and makes our photography interesting,.