I had the same issue as well because l was configuring two farms - search farm and content farm. Since my WFEs in content farm were purely WFE servers and no query role assigned to them. There is nowhere on the script where you can add WFE servers and the script will be looking for the servername on the autospinstallerinput.xml thats why the error does not come on app servers because you might add them to host central admin within the script.
Are your WFEs going to be used as quesry servers as well? The way l managed to run the script on my content farm was to add the WFEs servers as quesy servers even though there was no search service application configured in content farm so that role will not be added on the WFEs but if search service application is configured within the farm and you do not want these WFEs to have query role then my work around will not work.
The other option maybe will be to add these WFEs as query servers and if you do not want them to have query role assigned to them you will have to stop the search service application on all the WFEs.
Are your WFEs going to be used as quesry servers as well? The way l managed to run the script on my content farm was to add the WFEs servers as quesy servers even though there was no search service application configured in content farm so that role will not be added on the WFEs but if search service application is configured within the farm and you do not want these WFEs to have query role then my work around will not work.
The other option maybe will be to add these WFEs as query servers and if you do not want them to have query role assigned to them you will have to stop the search service application on all the WFEs.