What is the effect of R79 mounted on the mother board?
Spike noise filter for Power Profile in Smart Snippets?
The 10 Ohm resistor function is to simulate the coin-cell battery voltage drop which typically is about 50 mV for 5 mA supply current.
This 10R will cause a voltage drop of 50 mV for 5 mA Rx Tx peak currents. For having this supply voltage drop, J24 has to be removed.
When supplying from the LDO @ 1.5V (J23 open) the jumper J24 should be placed since the voltage drop from the 1.5V battery is much lower.
Normally we test with J24 always placed.