Props to him, modding games on the OG Xbox was a pain based on the conversion process and some of tools (or lack thereof) that were required to get anything done. Battlefront 2 was one of the easist games to mod because Pandemic released the source code, but you still needed a separate tool to rip and convert the textures/MDLs for the Xbox version of the game because they were packed different from the PC version.

Halo 2 was easily one of the most difficult games to mod, mostly when it came to AI logistics, as they had some of the best AI in the industry, even to this day. It would take hours to bake the AI into maps and required a lot of tooling to get them work right, but they were procedural to the map, which was awesome because once the logic was baked in, they could react and do things independent of needing node graphs for map plotting.

In short, modding Xbox content is something that was practically a full-time job just due to the complexity of it all and the limitations. This guy is definitely very humble because a lot of people just have no idea how much work he had to invest into creating a lot of custom content for a game like that, which a company is using without having given him anything for it in return.