I reused a former wooden book end to make that first version of back stop. I just had to open two apertures into the base so that bolting the accessory on the table. The two others opened in the front face aim the same purpose but with the planer fence.

After making the two repositioning gauges I had a third element left and rather than getting rid of that remnant I thought it may turn into a back support for the rip fence. The cast aluminium base of the fence locking on a steel round bar do not need help and the metal stop of that fence extension is far more suitable in conjunction with the power feed unit. But that small device (150x50x38 mm 6x2x1"1/2) doesn't require much room to be put away and might sometimes help. Wait and see. You may read about the initial project in that document.

So the back support aims to prevent the parallelism to be distorted when the operator needs to apply a strong lateral pressure on the fence. The base was machined into a single piece of wood and its bottom runner fits the gap between the saw and planer tables and leans against the infeed planer table when set. Despite the narrow runner I stuck a strip of sand paper so that locking without too much pressure of the bolt and mostly without any tool. I had many doubts about the effectiveness of that lock mechanism but was amazed how fine it worked. The gauges are shared elements that came from the side table extension.

Although that back support looks like the repositioning gauges it can't easily replace their function. Accurate and quick repositioning requires the gauge to be set as clause as it could from the lock mechanism which means right above the steel round bar on my machine.