There's surely someone more qualified than me that will probably jump in, but I can say I've purchased over $4000 in gift cards from Raise with no issues.
I imagine you could check and see if you can combine gift cards, and if so buy a cheap one from a big box store and then combine the amount from your raise.com card onto the physical card, but YMMV on that route.
What I intend to do on my trip the first of August is to use the raise app to buy a gift card the day I go to T-Rex. Usually I get my e-card within a few minutes of purchasing it via the Raise app. That way, I can use it that evening and not worry about the possibility it get's used.
Raise also has a 100 day guarantee that the total you purchase will be available; if you did buy now and the card was emptied you would get a refund from them. So there's that...hope that helps.