I'm not sure how trivial this is but as I haven't seen this done it might help in some tight DC layouts. It's basically a reversing loop on a regular continous loop you can use in any direction and takes no extra space except the crossover itself. I hope this might be useful.
Reversing Loop Angst! - PSX-AR & Kato Double Crossover (N Guage)
Cancers, Free Full-Text
Double-crossover reverse loops
Frontiers Crosstalk between dendritic cells and regulatory T cells: Protective effect and therapeutic potential in multiple sclerosis
Frontiers Mitophagy in Cerebral Ischemia and Ischemia/Reperfusion Injury
Cancers, Free Full-Text
Reversing Loop Angst! - PSX-AR & Kato Double Crossover (N Guage)
Kato 20-210 double crossover - what am I doing wrong ? - Track Systems - JNS Forum
TRod's First Layout - Page 3 - Layout Planning - JNS Forum
Frontiers 14-3-3 proteins—a moonlight protein complex with