Vanguard or Betashares as brokers and as ETFs after Maxing Out Super?

I (40M) have been maxing out my super contribution and should finish using my unused concessional contribution cap by the end of this financial year. My super is with AustralianSuper at 100% High Growth Pre-Mix - current balance $280k.

I've been investing $500/month in Vanguard High Growth Index Fund (Managed Fund) via Vanguard Personal Investor - current balance $35k. When I started, I chose this because I wanted to auto-invest a small amount per month, and brokerage trading costs made it uneconomical to invest in ETFs. Back then, fractional ETFs weren't a thing.

Now that I can invest more, I have started looking again and realised Betashares offers free ETF trading with fractional ETF. I'm considering switching to investing in ETF via Betashares and moving my current balance over to ETF to consolidate.

Has anyone switched from Vanguard Personal Investors to Betashares Direct? How's your experience with Betashares compared to Vanguard? Or are there other platforms/brokers I should consider and why?

I'm also considering whether to switch from VDHG to DHHF to lower costs from 0.27% to 0.19%. However, I'm a little concerned with the 16,000 to 8,000 securities reduction in market exposure and the loss of fixed interest exposure. Why should I switch (or not switch) to DHHF?

At the same time, I think I should ideally invest in the same proportion as the global market, so both DHHF and VDHG are overweighting Australia by a lot - over 35% in DHHF/VDHG vs <2% of world market cap or <1% of world GDP. I'm already overexposed to Australia's economy via my job and super, I probably shouldn't extend that with my non-super investments.

So as an alternative, I'm considering boosting my international exposure with VTS (0.03%) + VEU (0.04%), or BGBL (0.08%) / VGS (0.18%). With VTS/VEU, there's the question of what's the correct % mix and the need to rebalance them myself regularly, as well as tax inefficiencies due to them being US-domiciled funds - but they would give me broad market exposure with 4,000 + 3,500 companies. BGBL seems better in that it's a cheap one-stop international ETF, but the Solactive index seems less well recognised as VGS's MSCI index - and both only provide exposure to 1,500 companies in developed countries.

Of course, the easy/lazy/analysis paralysis way is to just stick with VDHG, focus on earning/investing more, and hope it works out.

I'm hoping to retire by 60 if everything works out. By my calculation, 0.1-0.2% difference in fees would cost me 2-4 months delay in retirement. Not great, but probably not as bad as making fundamentally wrong investment allocation decisions. That said, unexpected career/health/family/economic crises may have an even bigger impact - either forcing delaying retirement to 67+ or forcing an early retirement.

What would your recommendation be for ETF investments and why? What are some flaws and omissions in my considerations articulated above? Anything else I should consider?