I did a similar thing. But for some reason, my frist device broke when I soldered the USB OTG adapter in place (maybe I soldered too hot?) so on my second try I just put a small dab of hot glue on the side without the contacts. Works just fine
If it works, it works XD haha. I've made 3 so far and the only issue I had was on the last one it came with a different firm that had a stripped down version of busybox. I just flashed OpenWRT to it then followed the normal procedure