Should I be using two 2 brokerages?

First of all, you can own more than one brokerage.

It would be prudent to do a cost comparison (i.e maintenance fee, trading cost, custody fee) and understand your average volume of trades per month to reach a decision. Other factors include service support, user-friendliness of the brokerage app/tool, type of assets you can invest should also be considered.

Do find out more about the cost of account transfer (i.e IBKR to Tiger, or vice versa) should you intend to do so in future.

Last but not least, do find out more are there any other action you have to fulfill (apart from upfront fund deposit to get the free DIS share), before initiating cancellation of your Tiger account.

Do your due diligence, know your liability.