Compatible Bracket for Rackmate TT

No 'issue' but I have the Deskpi Rackmate TT and need some clarity on the approach before I contribute any files

The bracket is 170x89(2U) with 2 standard labstack openings but as you can see there is not enough room for a 3rd bay so I made a smaller (half labstack? its 20.666mm wide) so the questions are.

- Is it useful to keep the smaller opening for shenanigans?
- If its best to only have 2 openings should they be equal distance from the side and each other or should they be in the middle as close together as the other brackets have it?
- Am I missing a trick to make this space even more useful?

未指定源文件、测试或入口点；先与 maintainer 澄清预期的 Rackmate TT bracket 设计。由于开口布局和较小开口的实用性仍未确定，因此贡献尚未定义为完成。

由索引模型根据 Issue 内容生成。