有懷疑最緊要睇原文
https://www.gov.uk/government/publications/hong-kong-bno-visa-policy-statement/hong-kong-british-national-overseas-visa-policy-statement-plain-text-version
In order to qualify for settled status after 5 years, visa holders must meet our rules for continuous residence in the UK, which allow for absences of up to 180 days in any 12- month period. Once settled status is acquired, it may be retained despite absences from the UK of up to 2 years but may be forfeited if absences are longer without good reason. If after 5 years the visa holder does not apply for settled status or is refused, they will be expected to leave the UK and may be removed. Those here temporarily or with settled status who commit criminal acts may be removed.