Ok thanks on the clarification and explanation. It fits with what I observed and what I might expect. Sooner or later I'll have amassed enough information to make the "missing manual".
Most of the DIPs which are documented are for memory setup.. The remaining 8 or 9 switches are marked as "reserved" DO NOT CHANGE, on the settings charts. One of which is conflictingly marked as either "reserved" or "I/O delay".
There's several default factory soldered-in jumpers like so:
3-position, CLK12. With 1 & 2 closed. Likely set for the 8MHz speed judging by the label.
3-position, SX1. With 2 & 3 closed.
2-position, SX2. With 1 & 2 closed.
3-position, SX3. With 2 & 3 closed.
3-position, unlabeled, no stake connector, no Bergman shunt/cap
There are 3 for cache configuration. These are pointed out in the memory config chart. And they're selectable.
There's a 2-position, unlabeled, no stake connector, no Bergman shunt cap, jumper spot near the CMOS area. Might be for shorting and clearing CMOS.
There's some other unpopulated spots what I think are for 0-Ohm resistors. Larger spacing than jumpers, for more convenient PCB trace routing. Likely for yet more options.
I have a 33MHz version of this board laying around. Would be interesting to compare the two.
NB: Not really looking to hack or overclock this board. It performs pretty well for its speed grade and feature-set. If I need speed I'll just use a modern PC.