Don't forget "CONFIG_EXPERT_STACK_SIZE" for 4k x86 stacks.It's a subjective category and no amount of talking will bring any solution here.
It is brought up now and then partly because the use of the
term EMBEDDED that is so overloaded that it is not fun.
Someone should kill it and replace it with something saner.
CONFIG_EXPERT_TEXT_SIZE
For stuff that the expert can toy with which mainly
has text size impact and some documented performance/functionality impact.
The possibility to select a subset of CPU's may belong here.
CONFIG_EXPERT_DATA_SIZE
Likewise where what we save is more data than TEXT.
For example where we lower the size of a hash bucket etc.
CONFIG_EXPERT
For other stuff that no 'ordinary' user will need to change
but the expert may find it usefull.
Everything we hide under EMBEDDED today would fit in the
categories above.