You’re killing your car. Starting a diesel letting it idle for 20 mins to warm up. Then revving it high to blow out the cobwebs is causing nothing but problems. If you’re not using it, don’t use it. Slightly over inflate the tyres then leave it alone if it’s just six month. Then when you put it back on the road buy a new battery or second hand from a scrap yard and drive it normally for about and hour. Mostly under load.(Not revving it, at motorway speeds normally). It’ll be fine…. I’m a mechanic btw

I’d check you haven’t got the spacers on the BB. Fully tight it should still have some preload movement in it, that is taken up by the adjuster on the NDS. I would remove the BB and check for 2 aluminium collars on either side. You could be pushing out to 78mm.