Yes, good tip Will. I guess I could also create the arcgis-logsettings.json file
{"logDir":"e:\\arcgisserver\\logs\\","logLevel":"WARNING","maxErrorReportsCount":10,"maxLogFileAge":90,"usageMeteringEnabled":false}
in the e:\arcgisserver\config-store folder, and manually create the logs folder in e:\arcgisserver where it should be.
But still unclear as to why the installer allows me to point a the e drive for config-store and directories, but insists on the c drive for the logs folder.