There are a few other "loopholes" in the RC, but I think this one makes sense... The RC technically allows burai's as long as they are not "unreadable or ambiguous". The rule lists "burais" as an example of an unrankable issue, but only when they do not have "straightforward slider borders".
(Grammatically, "straightforward slider borders" modifies both "burais" and "hold sliders" so you should read it this way, not "burais (all) and hold sliders (but only when they don't have straightforward slider borders).)
Burai's with predictable slider paths have already seen use in the ranked section, but they are currently being used in very rare instances.
Some examples like:
It is not a stretch to extend some of these elements and create small bumps and grooves that are potentially burais but play well. Furthermore, using angle shifts would make the slider explicitly rankable as it is now mathematically not going over itself no matter how close to a burai it may appear.
Example of ranked sliders:
This is not a burai as the slider never actually goes back on itself due to angle change:
Similarly, sliders like this don't break the rule for burai's either because the slider never actually goes back on itself and doesn't qualify as burai to begin with.
People are pushing the boundaries of slider creation in part because the "tech map" meta is evolving to include more creative and unique slider patterns. That's one of the recent characteristic changes in "wub" or "experimental" mapping etc... Whether this rule is changed or not, there are already a lot sliders that technically do not break the rule to begin with.