I would leave the installation of structured cabling for (multimode) fiber cables to a professional. A multimode fiber installation cable without connectors should be terminated in the wall outlet by a specialist with the right tools. This task requires special equipment, expertise, and measuring tools to check attenuation and ensure the link is good, which isn't possible without them.
If you want to save money and since devices are usually connected in a chain, you could simply drill a hole through the wall between adjacent rooms and run the fiber cable through it. You can then neatly route the cable using self-adhesive cable channels (Available at any hardware store), such as sticking them onto tile trim. While the adhesive might not hold well on its own, you can secure it firmly with double-sided Tesa Powerbond tape (three small squares along a 1.5m length: front, middle, and back).
Cabling example: Random setup of "3 Rooms, UFX III, 2x 12Mic"
|---------------Room1---------------|Wall|---------------Room2---------------|Wall|---------------Room3---------------|
UFX III---------------->-------------------12Mic#1-------------->--------------------12Mic#2
| SC/LC (OM4) LC/LC (OM4) |
| |
+---------------------<----------------------------------------------------------------------+
SC/LC (OM4)
So called "patch cables" (with plugs) are available up to 30m or even 50m. The only problem by using patch cables could arise, if 50m is the maximum and not sufficient to connect 3rd device back to the first.
Maybe for this you might need "structured" inhouse fibler cabling.
If you should do this then base everything on OM4 cables, this is the new de-facto standard also for computer networks.
For higher speeds (10 Gbits and higher) longer cable length are supported.
Not needed for audio / RME, but it has about the same price as OM3, so better use OM4.
It is best not to mix OM3 and OM4 cables in one communication path otherwise you get a higher dampening which is not so beneficial. I would avoid such things as it is not clear when exactly problems could arise because of higher dampening.
And this situation can happen easily with a mix of inhouse and patch cables if it is not clear what has type of cable (OM3 or OM4) has been deployed. Even worse: in the past OM3 and OM4 had the same aquamarine color and could not be distinguished easily (only by measuing, but who has measuring equipment lying around for that purpose....).
Therefore for OM4 a new standard has been developed (mainly in Europe in use I read) to use Erika Violet color, so that OM4 cables can be recognized much easier and so that you do not have to measure.
For all these reasons I would - if possible - stick to OM4 cables with this Erika Violet color!
If you should have already structured inhouse fiber cabling, you should check what this is, OM3 or OM4 and buy then the same type as patch cable.
The ALVA cables are SC cables, only suitable for the UFX III which has such SC plugs.
The ALVA patch cables are available up to 50m, the cable drum even up to 300m or longer on request.
But I do not know exactly what this orange color code means, OM3 or OM4.
If you want to make business with them, ask if they can (ideally) provide OM4 in Violet color
and whether you can get SC-SC and SC-LC cables from them.
Single mode is not needed, multimode cables can be 2km long between each of the devices in a chain.
Single mode supports up to 10km between each of the devices, is laser based, not friendly to the eyes, do not look into it.
For the 12Mic you can easily swap transceiver to get single mode (IF needed), but for the UFX III you would need to raise a special order so that they deliver to you a model with single mode. I would avoid that if any possible to make this device not "too special".
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14