From when I took up vaping in 2016 until Covid/Brexit changed things, I spent half the year in Spain and half the year in the UK, flying between Newcastle and Malaga and all I ever did was to put my vaping gear along with my wallet keys and anything metallic in the scanner tray and I'd simply say "That's my E-Cigarette" and neither the English nor the Spanish Security staff ever gave me a moment's hassle.
The kit travelled with me either in my pocket or in my hand luggage, and again no problems - in fact when I was new to vaping and the device leaked all over my shirt the Stewardess noticed it and said "Ah I see your e-cigarette has sprung a leak - hang on and I'll get you a cloth!"