I did a very simple hinge pin hold open device that cost me nothing , took very little time to install, and worked perfectly for my application.
I used a section of SS hinge pin like we use on our cowling installations, and three single eyelet sections of aluminum hinge material. One hinge eyelet goes on the lower/outboard part of the door and is pop riveted in place of a couple inner door skin rivets. The hinge pin with, a 90* bend in it, will slip through this eyelet and the outboard (outside of the eyelet) bent slightly to prevent it from coming out - so this hinge pin is free to swing. The two other hing eyelets are used to hold the pin in the open, and closed position. In the open position the eyelet will go on the door edge lip. In the closed position, the eyelet will be on the door near the fulcrum, down by the door hinge. Giving a little room on eyelet location, requiring a slight bend in the hinge pin will allow some spring tension in the pin that will hold the pin in the open or closed eyelet. I’ve done this on both of my RV8’s and they have worked very well, cost me nothing, and weigh almost nothing. I wish I had some pics, but I don‘t. Very simple remedy for a common need.