Best way to paint prefab room data for procedural map generation?

Hi,

I'm currently making a 2.5D game with dungeons that are procedurally generated from combinations of prefab rooms. Eventually, I'd like to use a simplified variant of cyclic map generation—for the time being, I'm more or less happy to slam rooms on top of one another, have them elbow one another for room, and slap some doors between them.

I am trying to come up with an easy, convenient way of painting the data for those prefab rooms, ideally with each in a discrete file, which the map composer will grab from when looking for rooms. I am finding that this is surprisingly hard, and I'd love if anyone knows of any tools that can help.

I'm imagining that room data consists of some version of the following:

1. A layer determining basic tile type: Wall, Floor, or None.

2. A layer containing metadata about the tile. For instance, flagging wall sections that can contain doors.

3. A layer containing information about tile items. For instance, "this tile contains an altar," "this tile can contain a store."

4. A layer containing information about entities occupying that tile. For instance, "hard enemy can spawn here."

No view layer stuff, just data.

Earlier today I spent a while trying to make a system based on REXPaint, which works well with that layer system I had in mind. Unfortunately, finding a way to export its filetype to Unity seems weirdly difficult—NuGetForUnity wouldn't load the libs for any of the bespoke parsers (despite a whole lot of dependency wrangling and updating), and I have to imagine there's a faster way to what I want than rolling a parser myself. It also exports in XML and .txt, but it loses a lot of information in doing so which would make actually painting the room data much clunkier than it has to be.

Is there a better way of doing what I want to do?