I find trading UK stocks crazy expensive largely because of the extortionist stamp duty of 0.5% of transaction value, making it impossible to do UK single stocks on a monthly basis. I wonder if you have to pay the stamp duty if you get assigned stocks through options?
https://www.gov.uk/hmrc-internal-manuals/stamp-taxes-shares-manual/stsm113030 so option assignment does give rise to 0.5% stamp, stay away from UK equity