Way ahead of ya there mate.Marbled hatchets are a sight to behold, I had them in a 40B for a while, but their reputation for jumping is well noted, IME...proceed with caution...supposedly, the silvers are even worse...I had to rescue, more than once, one of my marbles that jumped from the tank during feeding time, just because the lid was open, and it was poised and ready, lol. Mine have eventually died off, down to just one now, I won't replace them...too much anxiety with the jumping, IMO...be sure you have a tight fitting lid.
Those corys are gorgeous.
Almost the entire tank is covered by heavy glass lids, and the small slivers of space in the back to make room for tubings and such I've covered with a multi-layered cheesecloth taped tightly down on all sides and corners. Will keep your words of caution about feeding time in mind though lol.