In a perfect world, and from the plant's perspective, grow media would hold water on the surface of soil particles, in the internal pores of porous soil particles, and at the interface where soil particles contact each other. The spaces between soil particles would be full of air, from the top of the soil column to the pot's bottom. A limited oxygen supply due to excess water retention is extremely common in all media comprised of very large fractions of fine material (peat, coir, compost, topsoil, sand, composted 'forest products', .....) because a medium's level of water retention is driven primarily by particle size.
When particle size is small or fine, water is held between soil particles at the expense of air porosity. Most commercially prepared media hold between 3-6" of excess (perched) water at the bottom of the pot. You can see that your pot ensures that after a thorough watering, there will be a level of saturation at least as tall as the distance between the opening on the top of the molded cone-shape to the pot bottom. So, if the grow medium you choose holds 4" of excess water at the pot's bottom in containers that have a drain hole through the bottom of the pot, and the ht of the vertical protrusions are an inch tall, it would add 1" to the ht the saturated layer would normally reach. Instead of 4" of excess you would have 5".
From some grower's perspective that might seem a good thing because it would significantly increase the intervals between waterings, but the extended interval between waterings comes at a price, that being unnecessary limitations on root function and an increase in the probability of damage to root health.
If it was my pot, I'd leave existing cones and holes, but make at least 2 more holes by heating a large nail or screw and melting through the plastic bottom with the head of the fastener; this, because melting the hole through is much stronger than drilling, which produces crazing (small cracks) caused by the drilling process, and 10 gallons of medium + the plant will be quite heavy.
Al