@Michael Jackson good question, and honestly one more people should be asking before they just slap an antenna on and wonder why they're getting 10% of the rated range.
The short answer is the RF front-end on the MultiNav Pro+ is already matched and optimized on-board — the 50km spec is achieved with the module as-is, no external matching network required. The design includes the PA, LNA, and antenna interface tuned as a complete system, so you're not expected to roll your own matching components to hit those numbers.
That said, antenna choice still matters a lot in practice. If you're using the recommended antenna type (or something with a similar impedance profile), you'll be fine straight out of the box. Where people sometimes lose range is when they swap in a wildly different antenna without accounting for the impedance mismatch at the feedpoint — you don't *need* a balun or matching network in the traditional sense, but you do need your antenna to be playing nice with the 50Ω interface the module expects.
For your telemetry setup specifically, I'd make sure whatever antenna you're running is actually designed for 2.4GHz BLE frequencies and properly terminated — that'll get you much closer to the headline spec than any additional RF components would. If you're doing something unusual like a custom antenna or running coax over any significant length, that's where I'd start looking more carefully at your link budget.
