An advantage of the MSI version is that it is on the %PATH% after installation, without any portableshell.bat invocation.

Fair enough - but if I wanted to have a Strawberry perl that was "on the %PATH% after installation", I would add a portable Strawberry Perl permanently to the path, and stay clear of the MSI.
I really don't ever want to be encumbered with the MSI version(s) at all.

Cheers,
Rob