Here's a quick mod I made for the C&C Remastered release from 2 days ago. It lets you build structures with a gap of 1 tile between structures (ala Red Alert 1).
Download link: https://steamcommunity.com/sharedfiles/filedetails/?id=2122093636
Source code changes (search for "FluffyQuack" to find each change): https://cdn.discordapp.com/attachments/449840053049360388/719894030749663292/TIBERIANDAWN.zip
And if there's anyone else making mods for this, here's a post I wrote with some details about how to release mods for C&C: https://steamcommunity.com/workshop/discussions/18446744073709551615/2290590708538477909/?appid=1213210