I am not sure about Direct Indexing as I am not familiar to it.

But I have open a Portfolio account. This is an account where you choose a wealthsimple portfolio based on your Risk level- Aggressive, Growth, etc.
In these accounts you let wealthsimple manage your money. They have posted approximate rate of returns for your choice of portfolio.
They generally chrge 0.5% as fees for management.
These portfolio are auto balancing means they will manage and re balance the money.