I was able to run the command but it returns "Template already exists". I was also unable to delete template from SAM interface - delete button is grey'd out. I don't see any switches to force overwrite.
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c:\Program Files (x86)\SolarWinds\Orion\APM>.\APMTemplateImporter.exe -includeRe
adOnly .\DefaultTemplates\AppInsight*
SolarWinds Server & Application Monitor Template Importer
Importing Read Only Templates
Found 2 template files.
Template files to add 2, legacy template files 0.
Processing file ".\DefaultTemplates\AppInsight for Microsoft Exchange.apm-template"
A template named "AppInsight for Exchange" already exists. This template will not be imported.
Importing 0 new template(s).
Processing file ".\DefaultTemplates\AppInsight for SQL.apm-template"
A template named "AppInsight for SQL" already exists. This template will not be imported.
Importing 0 new template(s).