To little surprise given that Reiser4 doesn't see too much optimization/feature work these days, Reiser4 tended to struggle compared to today's EXT4, F2FS, Btrfs, and XFS competition that are within the mainline Linux kernel. In fact, it's already been a decade since Hans Reiser was last able to contribute to the file-system's development and since then there has just been Edward Shishkin and few other contributors. Given the small bus count for maintaining Reiser4 and the lack of any corporate sponsor, besides the lackluster performance, it makes the likelihood of using Reiser4 in production a risky bet given the uncertain future.

Good point, I would agree by looking at the code, but testing it in my test server shows that I can't use it in #submit-maps anyways. Since only testers can use the command, I don't think we need to investigate it much further