Hello I wanted to see if anyone had any recommendations for a zoom lens that was up to 600mm for an R5. I have the EF 100-400 II but would like some additional reach for birds and other more rapidly moving wildlife. I didnt really see an advantage on the RF 100-500 with an f7.1 so I was trying to see if there were any other options others were using with the ability to focus rapidly and be sharp. Some of the reviews of the Sigma and Tamron lenses seemed to mention this, but I wasnt clear on how significant the issue was. I wanted something <2000 USD and more useable than a 7.1. I had hoped Canon would have done a 200-600mm f6.3 but alas no. Any thoughts or recommendations would be appreciated. Thank you.