Minor item here.
Can cash reserved for corporate actions events, please be shown in the account as blocked cash, rather than a withdrawal?
In between the point of being reserved, and the event being actioned - the current process doesn’t show this value in your account so does not show a complete picture unless I am reading things wrong.
Thanks 
Just to check if I get you precisely - you suggest having a separate area for the funds requested for corporate actions in the Account tab, right?
Yeah the cash funds disappear.
When you click at the top to see the account value 
, it has invested / blocked for investment / free funds.
I would have thought any cash put aside for a corporate action would still be shown in your account as funds blocked for investment, and not disappear from your account value until processed?
To be honest I’m not terribly fussed about it, but the value drops from your account until processed as far as I can see.
Thank you for clarifying this, @Dougal1984. It is indeed an intriguing suggestion. I’ve passed it along for consideration. 
If it helps, I think the colours are:
Free funds: Green
Funds blocked for trading: Yellow
Funds invested: light blue
So it could just be an additional:
Funds reserved for corporate actions: orange