I am no expert, so this is just how I would approach it.
I would probably try to add the cover points and the wall as a blueprint. So whenever you place it you would get the cover point. My next step would probably be to add a trigger and then have the AI react accordingly when they enter the trigger (e.g. Take cover, peek out, shoot, go back in to cover … if being fired upon stay in cover until the firing stops or there is a break and then peek out, shoot … rinse and repeat).
I haven’t tried doing this … my project(s) are approaching this mark but I haven’t gotten to it yet.
Epic is working on a hot spot manager which when used with their environment query system will be well suited for auto generated sets of areas on navmesh in the world. For now you can use EQS to generate sets of points in the environment either at runtime or offline through various trace tests, distance checks, angle checks, nav mesh tests, or your own tests. Check out the last two AI support streams for more info.
My project is doing the latter with preset cover points in the world until the hot spot manager comes online.