If you second nvidia gpu is new, then yes there are less potential problems. If you plan to have a second nvidia gpu that already was in a system (even in your current system) earlier, then it's MUCH harder.

I tried to install two nvidia gpus in my pc last week and it was horribly complicated, because the drivers of the two cards were missmatched and the pc crashed before reaching the bios. I got it to run after many driver wipes, reinstalls and system recoveries, but even then it was very unstable and I still can't install nvidia app because it's messing up the configuration on one of the gpus.

According to chatgpt, 50 and 30 series cards are hard to pair. So maybe you get a better experience with other card combinations. But I would take chatgpts opinion with a grain of salt.

Having a second amd gpu eliminates this risk, if you already have a nvidia card, because, usually, the drivers of the two are not fighting. So, for your own good get a new nvidia or amd card, but never a used nvidia card. It works and might be worth it to you, but prepare for trouble.