I just don't understand. You are spending thousands of Dollars for your hardware but you are complaining to spend just a few dollars for very good software.
I have to admit that I am only administrating 3 GPU Rigs + some Asic Miners with this software, but it saved me so much time that even a higher price would be worth it (at least for me).
I also do not understand why you need to change your mining software that often. Looking back the last months there was hardly much need to do so.
Maybe I am doing something wrong, I keep an eye on whattomine.com and for my AMD GPUs it was always daggerhashimoto (ETH/ETC) or Equihash (ZCL/ZEC), so there was no need to use X mining instances.
If you don't understand why GPU miners are using so many different miners you have no place GPU mining. Stick to your ASICs.
If you're using only one miner that definitely means you aren't getting the best speeds, mining the right coins, or really have that many rigs. By your own admittance you only have 3 rigs. You have 3 miners for each one (lets say at the most basic level, Ethereum, Equihash, and Pascal (assuming you don't dual mine or switch what you dual mine)), that means you need nine instance. You have 20 rigs, 40 rigs, that balloons quite a bit and there are decent bit more then three miners.
Yes, AMD mining right now is easier then Nvidia as far as miners go (you can mine Ethereum and not really do that bad), it doesn't work that way for Nvidia. The additional options for dual mining also increases the amount of instances you'll be using. However, that doesn't mean there aren't other options available for AMD, you just have to dig a bit for them.
It's not a 'little bit of money'. If you can't do multiplication you wont be able to figure that out.