It can get quite cumbersome to find out about key interrelations like arrays.

The alternative would be to have semantics in key names, with following advantages:

Do not encode any semantics into the key names. All semantic must be in metadata.

Nevertheless, there are guidelines (without any checks in keySetBaseName):

# is used to indicate that array numbers follow.
® is used to indicate that some information was encoded in the key name. This is usually only needed internally in storage plugins.
The UTF-8 sequence ®elektra (i.e. the 9-byte sequence C2 AE 65 6C 65 6B 74 72 61) is reserved, see key name docu.

There are, however, rules and conventions which syntax to use for specific semantics. The spec plugin guards these rules.

for consistency, whenever possible, metadata should be preferred
no escaping of key base names necessary
it is very unlikely that ®elektra collides with a real key base name a user wanted to have
®elektra makes very clear that there is a special reserved meaning
®elektra UTF-8 encoding decodes to "some character" + ® in many 8-bit encodings (including ISO 8859-1 aka Latin1 and Windows (Codepage) 1252, in the encoding C, however, you get `''$'\302\256''elektra'`)