Thank you for the informative response, and I apologise if I've come off rather brusque, but I initially started this thread because I figured it was those downscale filters that were the cause of my videos looking a bit blurry, but it turned out not to be, it just improves the look at lower resolutions (like 480p) which I appreciate, compared to my old recordings of Shadowplay. I'm recording videos for a portable device such as my smartphone, which is a tiny screen, and I just tried the few I made, and they look great on it. When I'm viewing them on my 1080p PC monitor, I just have to remember that 480p will look worse in fullscreen. ;) I'm also sticking with a low resolution like that so I can put as many videos on the 32Gb microSD card I have in the phone.
I don't even know what the bitrate is myself, I'm just using the "High Quality, Medium File Size" preset. I was also trying to retain the file sizes for the recordings in question, compared to the old ones, as my space is at a premium.
Also, my problem with NVENC is that sometimes, recordings I make have these nasty audio spikes in them at certain random points, which is a glitch with the driver or a fault with my Nvidia card, I don't know. But I've talked to others and they have had no problems, so I'm thinking it's the latter. I figured that by bypassing NVENC altogether, I can solve that problem. I don't really need it, as I'm only recording WinUAE output (a Commodore Amiga emulator) and my PC is managing fine at the moment. It's not as if it's something like Doom 2016! ;)
Anyway, thanks again, it's appreciated! :)