To answer the first part of your question, according to the Tk::Canvas documentation, find() returns a list:

This method returns a list consisting of all the items that meet the constraints specified by ...

However, you are storing the result of the find in a scalar, and as such are getting only the last ID (which is what you always get with a list --- not an array --- in scalar context). Try changing your code to

    my @id = $c->find( 'withtag', 'current' );
    print "\t item id(s): @id\n";
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(assuming you're not already using the variable @id) and see if that works. Good luck. Sorry I haven't had a chance to look at the second part of your question yet.