I use Netwealth, let's you have an allocation of 5% of your...

I use Netwealth, let's you have an allocation of 5% of your portfolio towards individual shares outside ASX300. To a maximum of 30% of your portfolio across multiple - i.e. 6 x speccies @ 5% each = 30% maximum. But when stocks go into the S&P300 the individual allocation changes to 10%, and then 20% in the S&P200 as well. It's not the cheapest platform but allows quite a bit of freedom.

I think Mason Stevens also allows speccies investment, but idk the limitations or thresholds atm, haven't looked into it enough.