It appears that internal pod links are not converted into Twiki style internal links. It seems the simplest way to do this would be to make the following conversions:
"L" ->[Pod::Simple::Wiki]-> "[[#here][here]]"
"=item * here" ->[Pod::Simple::Wiki]-> "#here/n=item * here"
(where /n would be a newline, creating a Twiki-style anchor on its own line right above the corresponding item, head, etc.)
It looks like something should be happening in Pod::Simple::Wiki::Mediawiki but it's apparently not even being called for internal links. I could take a stab at adding this myself if you could point me in the right direction.
The Twiki module predates proper link support in Pod::Simple so that is why links aren't handled.
If you would like to add it that would be good.
Copy the mechanism from the Pod::Simple ::Wiki::Mediawiki module and adapt it to Twiki. Maintain the surrounding style and add some tests. Again copy the Pod::Simple ::Wiki::Mediawiki tests.