If you are looking for some powerful SO for your routers, modems, repeaters I can say that you should give a try to OpenWrt. I tried it and I install in my two devices here:
First I installed in my TL-WA850RE, using the default firmware and I had no issues. Set it up using the GUI Luci, and it worked well as expected. Seems that it works better than the original firmware, and I have way more options to set up this little repeater. Actually now it works like a regular router as well as a repeater. OpenWrt makes any device a repeater easily, I tested it with my second device.
My second device TL-WR841N, it’s a bit more powerful, but it has only 4MB of storage, and it is a problem sometimes when you want to install a custom software. I had installed the main latest trunk, it worked but I had no GUI. Then when I tried to install the GUI got issues with my storage. Using the forum I was able to find another way, and all is described in the forum, click here to check.
After installed the GUI I was able to set up my network quickly. Also it’s possible to make any regular router a repeater, I tried here and it works pretty well (look on YouTube how to set it up). Also I was able to define some host names, and point then to some specific IP address, make my local network more accessible.
OpenWrt also has a full dashboard to control what is going on in your network. If you like to change things and play with your devices I recommend that. Just be careful to not brick your devices, read the forum and act knowing that you may break something. Try to understand things before doing them, just it is enough. Good luck!