Update: Success! I was never able to find the specs, but I did go ahead with the Porter install. The Porter was from a Clementine starter set (metal side rods, horizontal motor), and the board was stolen out of an EZ-App FT ($50 off Amazon some time ago; the FT chassis will be rewired to run directly off track power). The board is mounted in a side tank, and extends into the coal bin in the cabin. Splicing and soldering everything in was a bit of a pain (including replacing the Porter's original headlamp with the LED from the FT), but it all works. I'm using a 6A power supply from Amazon that has either 15.2 V or 18.1 V output (not as advertised, but close enough). Around a 4' diameter 180° curve, the loco starts slipping with 5 lightweight (Big Hauler or similar) freight cars and a bobber caboose, pulling 0.67A at 15.2V when fully slipping (caboose held in place). The board does not trip on overcurrent protection.
As for BlueRail, I'm well versed in it, and am on the waiting list for a G scale board for my Climax.
As for BlueRail, I'm well versed in it, and am on the waiting list for a G scale board for my Climax.