The two conductors in the wire are insulated separately and sort of lightly attached so it's probably OK if done carefully.
If this was me, I would've threaded the lights through the big triangle piece directly and attached with zip ties, instead of modifying the cord.
Also, the comment at the end to use "hooks" beats the whole point of using magnets.
Installing a nondescript hook up there would be a one-time use of a ladder which could just be borrowed or rented from somewhere. Future decorations can be done with just the extending pole and magnetic attachment.
Comments
The two conductors in the wire are insulated separately and sort of lightly attached so it's probably OK if done carefully.
If this was me, I would've threaded the lights through the big triangle piece directly and attached with zip ties, instead of modifying the cord.
Installing a nondescript hook up there would be a one-time use of a ladder which could just be borrowed or rented from somewhere. Future decorations can be done with just the extending pole and magnetic attachment.