In 2022, Martin Niec sent me some pictures of some STEbus backplanes he was making.

These omit terminations, as he wanted them to be usable in other buses (so long as they share the same power and ground pins, which will exclude VMEbus P1  and ECB bus boards).

The ground and power rails are fixed at the edge-most pins. This allows large current-carrying copper lands.

For more than a few slots, current consumption may be large, so plenty of power connections are advisable.