What can I do about my tax situation

So upfront this is not a brag at all more of questions out of frustration.

I paid $82k in tax last year and I still get a bill for another $12k owing inc div 293 I really want to get this down.

My background I'm a 40 year old male, earn $350k, have $290k in super and a defined benefit set to pay $115k annually at 55. I have 2 kids, wife works as well approx $135k pa.

Assets:
– PPOR is fully offset , remaining loan $580k , obviously $580k in offset. Value approx $1.5m
– $120k in a savings account
– $98k in ETFs ( 30%VAS, 60% ivv, 10%gold and Bitcoin)
– 2 X IPs basically neutral

I can't see the point in putting more in super for 2 reasons, one being I don't want to wait that long to access it and I will receive my defined benefit at 55 which will support me and my family.

At the moment I am pouring cash into those ETFs at $7k a month.

Has anyone got any ways I can reduce my tax liability ? I was thinking of borrowing as a split loan against my PPOR and lump sum that into ETFs just to use the interest as a tax deduction, but not sure if this is a smart idea ?

For example $600k @6% , would that be a $36k deduction at tax time ? is this smart or stupid to pay interest on this just to invest.

Any ideas or feedback would be much appreciated , thanks.