That's the bottom of my Slot.it Porsche 956 with an SP15B fitted into the standard oXigen & SSD-compatible chassis. The distance from rear end of the (standard) guide to the middle of the LED is 11.5mm - well within Dr_C's suggested limit of 19mm. It's been a while since I used the car on ARC Pro, but I don't remember any issues. I can test again at the weekend, if that would be helpful?
I also have three other recent Slot.it cars to hand (Porsche 962, Chaparral 2E, Alfa 155) that have the oXigen & SSD-compatible chassis and the LED holes in the chassis look to be the same distance from the rear end of the guide blade. So on the basis of the distances that Dr_C has calculated, I would say that the recent Slot.it cars that are marked 'oXigen & SSD-compatible' are ARC Pro compatible with a SP15B chip installed. For older chassis, it shouldn't be too much problem to fit the chip so a hole drilled for the LED is a similar distance from the rear of the guide. The semi-circular cut-out on the front of the SP15B should fit nicely around the front body post.
Of course, they need to run with a black guide as Andy says. The cars must also be set up in the app with the same colour they are linked to on the powerbase - 'the rule of three colours'.
One brand of cars that will be more difficult to chip with the SP15B for ARC Pro is NSR - especially with the triangular motor mounts - they will need an external LED to get within the suggested 19mm. And the white guide will need to be changed for a black one.