share transfer, page-10

You are correct; share offerings direct from the company do not modify the new averaged price on your trading platform.
The reason for this is that CHESS is only concerned about the recorded legal ownership of shares and the numbers issued. It does not concern itself with the price of shares purchased on market or by company share issues.
The accurate way to calculate the most recent averaged price is to:-
add up the total cost of all share purchases over time (including share issues). and to devide this by the number of shares shown on your portfolio spread sheet.
The number of shares held and shown on your trading platform will always be up-to-date as this variable is controlled by chess.