I think the big question is what editor you use and whether it preserves alternate streams? For example:
PS C:\scripts> Add-Content -Path style.ps1 -Stream tags -Value "colour;help;test"
PS C:\scripts> get-content -path style.ps1 -Stream tags
colour;help;test
PS C:\scripts> ise style.ps1
PS C:\scripts> get-content -path style.ps1 -Stream tags
get-content : Could not open alternate data stream 'tags' of file 'C:\scripts\style.ps1'.
At line:1 char:1
+ get-content -path style.ps1 -Stream tags
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : ObjectNotFound: (C:\scripts\style.ps1:String) [Get-Content], FileNotFoundException
+ FullyQualifiedErrorId : GetContentReaderFileNotFoundError,Microsoft.PowerShell.Commands.GetContentCommand
Powershell ISE doesn't preserve the tags stream, so you would have to reapply the tags every time you edit something. I think most other editors would have the same problem.
Also, you should be using some form of source control on any scripts you write, so again the source control system will probably strip tags.