You’re a great resource for finding bugs, Selentic 
Thanks for reporting the bugs you encounter. Your first issue is an issue I thought I had corrected, but it seems I only corrected it for displaying tiles for pathfinding and not for visibility. To fix this you should make the following changes to the Spawn Tiles In Range function:
The second thing you are pointing to (the branch that is always true) is just a temporary branch I forgot to delete after testing. The reason it does not work is that the AI uses it to determine what tiles it can move to for attacking player units. If we allow the AI to include tiles where LoS is blocked because of walls the AI may then attempt to move to these tiles when attacking. However, later down the event graph of ATBTT_AI_Controller Find Path to Tile in Range is set up to take walls blocking cover into account by default. This function will attempt to find the best tile for attacking the target, but may not find any (since all might have LoS blocked by walls), return false (0) and have the AI unit move to index 0. You could set Trace Visibility to false for the Find Path to Tile in Range in the AI controller and I think it should work as you expect it to, but I think it is better to instead set the collision of any walls you want to be able to attack through to not block RangeTrace.
I will put these bugs on the list of things to fix before the next update. Thanks again for letting me know.