For certain account settings, it may be very common for an account to only have a single child account without anything on its own, like
+ Assets
+ Amazon
| + Points
+ BCinemas
| + Points
+ DigitalOcean
+ Credits
I think it would be more compact and look nicer if we fold them together, something like
+ Assets
+ Amazon:Points
+ BCinemas:Points
+ DigitalOcean:Credits
Similar to how GitHub folds directories with a single subdirectory (see .github/workflows, src/fava, and stubs/beancount):

WDYT?