What do you call a person who systematically gets involved in (or creates) projects that are too big and too detailed, which means that some of them will become a challenge beyond their abilities?
For example, if such a person decides to create a photo-album of their holiday, they end up taking photos of everything and then, when putting together the album, they take so long there's a chance the album won't be finished before one or two years (or not at all, as a new mega-project may in the meantime have taken up the person's attention).
Or imagine the person decides to create a database of their personal library and automatically goes about creating fields for every detail, including sizes and weight and, why not?, a thumbnail image of the cover, a field for the blurb and for a personal comment, and... (Yeah, I know, Goodreads already has all that, but we're talking about the type of person who'd still say Goodreads is missing fundamental fields so they must go and create it all from scratch).
EDIT: Conversely, some of these projects can be small: say, making a yule log so detailed it does take up the appearance of a log (uneven shape and edible mushrooms, berries and leaves as realistic as possible). Or instead of producing a database from scratch they can buy the software that offers the best chance of being detailed and then they use it to the utmost.
I'd been using the term 'megalomaniac', because the projects are always 'mega' and there's definitely a 'mania' driving these urges for 'mega projects', but once I started reading up on the term, I realised it didn't quite fit the bill, as the person in question doesn't necessarily think themself better than others, nor is there a need for praise over the projects. It's more of a personal need to go to the utmost detail.
'Perfectionism' may be involved in the process, but it refers to the need of doing something perfectly, even if the task is simple. I'm looking for something that focuses on the need to go big or go home.