TLDR; replace all hardcoded checks for US/USSR campaign faction keys/labels with using faction manager as single source of truth for Conflict faction config

Currently there are tons of hardcoded checks against specific faction keys defined in the Conflict game mode (m_sBLUFORFactionKey, m_sOPFORFactionKey and m_sINDFORFactionKey) and other parts of logic for example HQ assignment only selects HQs for the 2 faction keys defined as BLUFOR and OPFOR. If you wanted to make a 3-way Conflict mod (say USvsUSSRvsCN) it's currently not possible due to how many aspects of Conflict and it's components are statically checking for only 2 participant factions.

I have been working on solving this in a mod that overrides all the hardcoded references to the static participants defined in the Conflict Game mode as well as a few other things with dynamic checks against the configuration of your SCR_GampaignFactionManager which enables additional participating belligerent factions in the Conflict game mode, I have most of the core stuff working for additional factions just a few bugs left to iron out. Will post a link here once it's ready since it may be of use to other modders wanting this feature.

But really the vanilla faction system (as integrated into Conflict and adjacent features) should be fully dynamic and refer to the runtime faction manager config as a single source of truth, all static checks against specific faction keys and indicies in places like campaign, base and radio managers/components should be checking the faction manager.
Then we can have scripts dynamically adding/updating factions according to our needs and they should all "just work" with all of the vanilla Conflict features (base building, capping etc).

This functionality is required for a lot of custom FFA/TvT game modes focused more around dynamic player groups than predefined scenario factions.
Mods like WasteLand, Rogue Extract, Everon Life etc could all benefit from the factions system being more dynamic and factions being creatable at runtime via scripts
Most of these kind of mods just have a work-around solution like repurposing squads/groups as player factions which kind of works for the most basic use cases of grouping players but doesn't support all the capabilities that dynamic factions would for example integration with Conflict features and more powerful customization features like we could allow players to set icon colours, flag, which style of faction prefabs to use for bases built by their player group etc.