IO Loan on IP – Need clarification

Hey All,
I have been reading about IO loans on investment properties and just needed some help getting my head around it.

Scenario 1
Let us say I own an IP with a 300k IO loan and a 100% offset account.
Let us say I have 200k sitting in this offset which means I can claim 100k tax deduction on the interest portion of the loan.
I now decide to buy another IP and take 100k from the offset meaning I now can claim 200k of interest tax deductions.
I think that is right so far as all good.

Scenario 2
My question however is let us now say instead of IO on this 300k loan I go P+I with no offset.
Now instead of 200k in the offset I made extra repayments and only owe 100k on my loan so can claim 100k tax deductions exactly like in Scenario 1.
I now decide to buy another IP but now I have no money in an offset account so my only option is to draw the equity from the property which I draw 100k and am now back to 200k which I can claim as an interest tax deduction.

So from how i am viewing this it works out to be the same. Only difference is the hassles of having to go through the banks to draw the equity and I realise this would mean a new valuation and value may have dropped but I am thinking I have this wrong and there are many other considerations??