Regalia Forex Plus is ideal for frequent travelers, as it has 0% cross-country markup in USD, which makes it more versatile, and you can spend in AED in the UAE with no need to pay an extra fee beyond the initial USD load rate. The multicurrency Forex card is best for travelers going, and it allows loading multiple currencies (including AED).
So for your UAE trip, I suggest using the Multicurrency card loaded directly with AED might be more straightforward, as you'd lock in the AED rate.