Simple RAW for 5e V: The Disadvantage Strikes Back

[honeybunch]

Q164:

If playing on a grid, does the Wingwear magic item allow for unlimited flight? (ignoring any need for sleep or other bodily functions)

Wingwear is an uncommon item from Princes of the Apocalypse. It requires attunement.

This snug uniform has symbols of air stitched into it and leathery flaps that stretch along the arms, waist, and legs to create wings for gliding. A suit of wingwear has 3 charges. While you wear the suit, you can use a bonus action and expend 1 charge to gain a flying speed of 30 feet until you land. At the end of each of your turns, your altitude drops by 5 feet. Your altitude drops instantly to 0 feet at the end of your turn if you didn’t fly at least 30 feet horizontally on that turn. When your altitude drops to 0 feet, you land (or fall), and you must expend another charge to use the suit again.

The suit regains all of its expended charges after spending at least 1 hour in an elemental air node.

The variant (but very commonly used) rules for playing on a grid include the following:

Squares. Each square on the grid represents 5 feet.

Speed. Rather than moving foot by foot, move square by square on the grid. This means you use your speed in 5-foot segments. This is particularly easy if you translate your speed into squares by dividing the speed by 5. For example, a speed of 30 feet translates into a speed of 6 squares.

If you use a grid often, consider writing your speed in squares on your character sheet.

Entering a Square. To enter a square, you must have at least 1 square of movement left, even if the square is diagonally adjacent to the square you’re in. (The rule for diagonal movement sacrifices realism for the sake of smooth play. The Dungeon Master’s Guide provides guidance on using a more realistic approach.)

If a square costs extra movement, as a square of difficult terrain does, you must have enough movement left to pay for entering it. For example, you must have at least 2 squares of movement left to enter a square of difficult terrain.

Corners. Diagonal movement can’t cross the corner of a wall, large tree, or other terrain feature that fills its space.

I'm pretty sure that Wingwear is only intended to allow long term gliding, although I could be misinterpreting the designers' intent. In either case, is there any RAW reason a character using Wingwear and playing on a grid couldn't fly 30 feet diagonally forward and up each turn, more than counteracting the 5 foot altitude drop at the end of each turn?