Virgin Money or Newcastle Permanent

I have a variable IO IP loan with CBA for 320k (3.65%) which is currently fully offset. I am looking to draw down on about 150k this year (and maybe more in 2022) to invest in the sharemarket and am on the hunt for a better variable IO rate with 100% offset. Ease of ability to extract equity with the new lender would be a plus so I can continue to invest in the sharemarket. I'm not looking to buy more IPs but a modest PPOR purchase may be a possibility in the next 5-10 years so I am prioritising good rates over generous loan serviceability.

I've looked at Newcastle Permanent, Teachers Mutual Bank, Suncorp, Virgin Money and Adelaide Bank. I'm particularly interested in Virgin Money and Newcastle Permanent as they are currently offering 3k and 2k cashback respectively and this would help offset some of the refinancing fees.

There appears to be limited recent discussion about these two lenders here/online and the comments I've read have been neutral. Keen to hear from anyone who has used them/currently uses them or anything I need to be aware of or any other lenders I should also consider noting my circumstances.

Also, a question specifically for the brokers who might be reading this, would I be correct in assuming that Virgin Money and Newcastle Permanent do not offer upfront valuations to brokers? (It seems only the more sophisticated lenders like the Big 4 offer upfronts). I'm currently at 80% LVR with CBA so if I get a poor valuation and need to pay LMI with the new loan provider, I would hold off refinancing.

Thanks in advance.