So, with all the AutoDemo restorations being made by ItsEasyActually, supercoolsonic, DemKnux, etc., I recall a years-old Sonic Retro post by someone who found that one early chao garden from old footage and screenshots in the AutoDemo's files. After he/she was informed that placements were hardcoded into the EC garden (which he/she was trying to replace with the beta garden) he/she gave up abruptly. He/she did give a link to the .obj file from the AutoDemo to fiddle with on another post, but the link's been dead for a while. I feel there should probably be some consideration into making that a reality again with all this AutoDemo content being fixed and restored, given it's even possible. Finally, Shadowth117 made a PSO garden mod that replaces the SS garden, and the placements there look phenomenal, so I think chances are very high that the EC garden can be replaced too, if the harcoding can be bypassed or managed with. If not, oh well. We have AutoDemo Windy Valley Act 3, which the garden was ripped straight from. That's always better than nothing.
I'm pretty sure this is part of the planned future for supercoolsonic and myself. It's just a matter of when we get there and start working on it. We're in the process of getting a repo setup sometime soon actually, so maybe sooner rather than later?