There are different possible stages, though the details will vary a lot on what you are trying to achieve, what is on the market, your technical and financial means, expected volume, etc.
The easiest solution is to use development boards, which are not always very small, but usually have all sorts of interfaces, connectors and additional stuff which is very useful for prototyping (such as USB interfaces, configuration jumpers, several power sources, test pads, connectors for antennas and batteries and external devices, pins to use on a breadboard, LEDs, etc.), but of course takes space (and adds cost). You can often use those without soldering a thing.
This allows you to test the functional aspects, software, and so on.
For some products you can directly re-use such boards, if they meet your constraints.
The next possible solution is to use SMT modules. Those have the minimum components to run (in your case the 9205 needs additional components such as the SDR105 front-end, a PMIC...), but more limited physical interfaces. In many cases the only connections are just the solder pads, which may be more or less easy to manipulate (they can be just on the edges or you could have dozens of contacts under the module).
Many such modules include shielding and have been EMC/RF tested, which can simplify your regulatory approval process.
In some situations such modules will include an antenna connector (u.FL), a PCB trace antenna, or a ceramic antenna, and associated matching network. All the rest needs to go through the contacts of the module, which means you'll have this soldered onto a PCB which will then have the connectors for whatever your need (antenna, battery...) as well as buttons (reset? factory reset? configuration?), LEDs, and whatnot. Depending on the power source and what is inside the module, you may also need voltage regulators, battery charging circuits, USB ports... Don't forget that you'll need to program the devices initially!
Of course in this case, you ned to design your own PCB, have it made and assembled (or have the resources to do it yourself), which on every new version means time and money.
The final step is just to design your own full PCB onto which you'll have all the components you need and just those you need. In some cases it may be relatively easy, in others significant skills may be needed which you may not need when using an SMT module.
Note that the minimum quantities involved usually increase along the way: dev boards are sold by the unit, modules sometimes require slightly higher quantities, the chips themselves may have very high minimum order quantities (MOQ). 100K pieces to order directly from the manufacturer is common, and for some chips it's the only way to get them (others you can get for any quantity, but the price may be quite different depending on the quantity).
