first of all, I think that more legendary should have an unnatural way of spawning but via items (we are still talking about legendary) but I would like to add to that that certain legendaries lack structure (I am thinking in particular of groudon, kyogre, rayquaza, the time altar of the trio dialga, palkia, giratina deserves a structure I think and others), but to that I would like to add that as far as possible for the legendary giratina I thought that it would be incredible to create another way of spawning, basically recreate the inverted world (natural habitat of giratina in games, film ect...) and to put the time altar in the dimension (a bit in the spirit of the nether in classic mminecraft, a dimension reachable only in certain conditions for example after capture of dialga/palkia used a red chain on a portal or the time altar in the overworld), in the same spirit I had thought the same thing for arceus in ruins
Adding items to spawn legendaries and spawn methods would add even longer immersion to the game and the lifespan of the mod.
here are the ideas at first glance that I could submit to you (these are still ideas, you can very well refuse), I hope I have not lost you and not been too messy if you need more details contact me
Thank you for your work on the mod it is fabulous
Ayden_Off