Nice! Congrats on becoming a Goblin owner! (heh...not an official nickname for the F-35, but maybe it'll catch on) I got Eduard's mask set for the newer F-35s with the Z13 overcoat. I haven't decided if its going to be easier to use the masks or just go with the kit decals. The Z13 aircraft aren't quite as complex a masking job, but I had already started on my plan for painting with the Have Glass Grey first, and then putting the decals on top...and then Eduard released their mask sets which are designed for the lighter, Neutral Grey going on first.
Oh well...I'll figure something out. Not really sure how much I like the Eduard set anyway, since they elected to use vinyl for some reason, instead of the Tamiya-style paper masks they normally have. Something I ended up picking up though, to help with masking the leading edges of the intakes, was this set of masks I found on Ebay:
https://www.ebay.com/itm/225327856131
They're really nicely done, and its all the Tamiya-style paper material. Something I wasn't expecting when I bought it was all of the extra masks they have in the set. There are also masks for the GBU-31s, the wheels, the canopy (inside and outside), the exhaust nozzle, and the extra pods that Danish Goblins carry, all included in the kit. The GBU-31 masks will definitely come in handy, since I'm building mine in full, fangs out, "beast mode".