With all the different Chia forks coming out right now, including Flax, ChainGreen, SpareCoin, ChiaRose and now Chives there are a lot of farmers right now with multiple blockchains running on the same machine farming the same plots. But is it safe? No. Not it is not. Even if all the applications are safe right now, it is almost inevitable that a Chia fork will release that contains malicious code in some way.
What is the threat? The threat is to the files. If some sketchy fork has access to your .chia-blockchain folder they can mess with your Chia configuration without it being obvious, leading to reward theft. They can also grab the certificates from the ssl folder for your full_node and wallet service and perform malicious actions there. Chia is built with a permissive model that allows everything access to everything else assuming trust between services. When you start installing 3rd party software into that mix your services are no longer trusted and you are putting the whole system at risk.
Is there a solution? Yes. At the risk of sounding like an IT consultant from 2007 the answer is virtualization! On Linux the answer could also be docker, but segmenting this things with the best tool available is the answer.
In our latest How-To guide we have some step by steps instructions on setting up a Windows 10 Pro computer to host the plots locally and host a number of VMs for each fork so they have read-only access to your plots and nothing else. You might have to share your Active Farmer wallet key with them, but you should not have to expose your Chia farming system in order to farm a sketchy fork.