New to CWDM, few questions

CDWM newbie here with a few questions. Did my best to google and look at old posts.

Background: I’m getting 2 strands of fiber to create physical diversity around an existing fiber path. Goal is to dual home a few more things across this new secondary path and will need more fiber than available. Passive CWDM seems to fit the bill.

1. I’m looking at a 8 channel passive mux (https://www.fs.com/products/43099.html), what would happen if a noob new guy accidentally replaced a colored SFP with a standard LX SFP on a channel by accident? Are there optical filters inside the mux that prevent it from affecting the other channels?
2. Is CWDM okay to use on a multi jumped fiber path? Total distance is about 3 km.

• Got about 6 sections of outdoor fiber that will be patched together via patch panel (within link budget given attenuation and insertion loss along the way)
• Example: Switch w/ CWDM SFP | —— OSP —— | CWDM MUX in key building | —— OSP —— | patch | —— OSP ——| patch | —— OSP —— | patch | —— OSP —— | patch | CWDM MUX in data center | Aggregation Switch w/ CWDM SFP
• My only concern is that some wavelengths may have issues or more attenuation on some of the OSP sections. I guess this is where I should use an optical spectrum analyzer to test the entire CWDM wavelength? I can get it OTDRed and put a light meter on it.

That’s all I can think of so far. DWDM is not necessary right now, just trying to keep it simple. Thanks everyone!