Engines, thanks for the education.
Re U.K. all F35B, land and sea use, presumably this should enable the aircraft to ‘ski’ off road bridges and ‘land’ in the hole in the woods if future land strategy requires. i.e. a more flexible aircraft against increased wt, aka Harrier.
Also we tend the think that more weapons = more weight, which could be changing with new lighter technologies, except someone requires more range, more weapons, more … , or even a mini stealth AEW.