The business entity concept has to prevail. The accounting records are limited to those of the business and do not extend to the personal resources of its owners. The personal bank account of the sole trader is not the business account. Funds, for example salaries from another employment, paid into the personal account should not be treated as capital introduced nor should their spending at the supermarket from same account be regarded as drawings. Their personal funds are not an extension of the funds available to the business. The trader would need to make a conscious decision to introduce such funds.
Your suggested method is the same as mine namely importing business only transactions. So we don’t need a solution to a problem that does not exist.
If the trader were to draw up a balance sheet they may well determine that there is a cash balance. They may consciously left funds available from their profits to use to buy stock or further develop the business rather than taking them as drawings. It should be reported as such.
@B2 Bookkeeper remains correct.
Funds introduced by the trader would be reported under the Capital section but funds introduced by a director would go to the credit of their director loan account which is not part of the capital of the business. Lastly, I wouldn’t put a director’s personal bank account anywhere in the accounts; the Business Entity concept again.