wolframscript has a command-line argument -l:

-l, -local [KERNELPATH] Execute code locally using the specified path to the Wolfram Engine kernel. By default, KernelPath uses the most recent version of the Wolfram Language found on the local system.

So you can use Run or RunProcess and cobble together your own performance-comparison framework. ExternalEvaluate doesn't seem to support Wolfram as the target system, according to the documentation.