Thank you vinny, for providing the immigration rule information.
Having read the rules, It seems to contradict some other past posts say about what T2 cannot do, such as start a business or self-employment etc, because:
From 245HC(d) and 245HE(d), it says the condition of T2 are:
(iii) no employment except (2) supplementary employment
in Interpretation and Guidance is defined in Interpretation as:
other employment in a job which appears on the Shortage Occupation, or in the same profession and at the same professional level provided that:
(i) the migrant remains working for the Sponsor
(ii) the other employment does not exceed 20 hours per week and takes place outside of the normal hours
the 'other employment' mentioned above, in particular, employment
in Interpretation is defined as:
unless the contrary intention appears, includes paid and unpaid employment, paid and unpaid work placements undertaken as part of a course or period of study, self-employment and engaging in business or any professional activity.
Also nothing regarding own shares or being directors
My interpretation of the rule maybe be wrong and I would much appreciate if someone can correct it in the case it is misinterpreted.