Well the Program Settings, Exclusions, has an option to browse, use that to find the file you want to exclude and select it. That will import the path into Selected paths: box, before clicking OK, copy that path and use that in the standard shield exclusions.
The advanced options were also considered and I believe for the same reasons that the exclusions sections have been catered for any advanced option didn't progress.
I don't know what programs that you are using that have avast continue to detect them as malware. I have only two exclusions in the Program Settings, only three in the standard shield exclusions and that is in over three years of use. So I haven't found that it is so frequent that I need an advanced option to save adding them manually.