You might have a hard time finding much info. It is more common on some sailing dinghies, but I have seen this on a P30 and some larger boats. It isn't a common solution because I think the main use-case is to get the mainsheet out of the way and controlling sail shape without the clutter of a traveler and/or vang - more of a problem on smaller boats, typically. A variation on this that combines the bridle with the mainsheet is sometimes called a "Crosby rig". This gives you less control but is wonderfully simple. Probably not what you want, but it might help you visualize this.
There are several variations on the idea, but basically you have an upside-down "V" that forms the bridle. One line runs from the top of the "V" to either side of the cockpit. At the top of the "V" is usually a block and the mainsheet is rigged overhead. You can independently adjust either side of the bridle to effectively perform the same job as a traveler. Some people have them rigged cleverly so that they can adjust the tension of the "V" with one control and the port/starboard position with another - which makes adjustment more user-friendly, but does the same job as two independently-tensioned lines.
The reason I suggest this is that you can position that bridle anywhere - forward or aft, provided you establish strong attachment points.
Here's a simple diagram. The grey circle is the boom. The pink ovals are blocks. The blue line is the mainsheet and it just goes to wherever you want to route it - lots of options there. In your case, I would use a single bridle line instead of two independent lines. In that configuration, the length of the bridle is fixed, positioning that overhead block at a fixed height. Adjusting the bridle line just allows you to move that to port and starboard - like having an overhead traveler.
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