Flexispot E7 Pro Line order regret

I ordered an E7 Pro Line that is set to arrive today. I got very lucky and managed to snag one of the 60% black friday codes for this. Over the last week, I've started to have doubts that this model will be suitable for my needs. I am 6'4" and use a walking pad, and I am worried this might have too much wobble when brought up to full height. My desk itself is also quite a heavy piece of butcher block board, if that is relevant.

I reached out to support to see if I could possibly send the E7 Pro Line back to purchase the Plus Max, which I believe would be the most stable option. I offered to pay any of the additional shipping expenses and the price difference between the original cost of the Pro Line and the current Plus Max.

Support said I could return the Pro Line for a refund on my purchase and then start a second purchase on the Plus max. I explained that wouldn't make the most sense for me to do, because it would mean losing all of the heavily discounted savings from the 60% code. I'm not asking for the 60% to be applied to this separate item, but I thought my offer of paying the additional shipping costs plus the difference between the original Pro Line price, to be fair.