Same with my new JMJ. I’m so tempted to attack the lower cutaway and corner of the heel joint with a rasp (I won’t). No shielding on the JMJ either, not that it’s especially noisy, but I’ll probably add some copper tape at some juncture, especially as this seems like a great bass for recording.
I’ve been playing it a lot with a pick (too much watching Bobby Vega and Cody Wright videos) and it sounds great, especially as palm muting is a doddle.
The JMJ comes with Fender flats, which seem to fit the whole Mustang vibe nicely (medium scale strings seem to be the recommended length for any replacement strings). Because of the lack of overtones, it takes modulation effects really well, even low, open strings through an octaver track well.
Enjoy your new acquisition.
EDIT - Similar weight too.