Ive tried to do this and I could get my character to level 50, then reset it to 1 and level him up as many times as I want, but it doesnt grant me a high amoint of gems each time, only a few per levelup.
My first step was to find the value for my level, and at around level 6 or 7 I find like 4 values, save those, then search the values for my xp level and refine it until I get one search result. Then I change the value of the xp to 0, change the value of my level to 1 and have it reset to 1. Then I change the value to -1 and on leveling up, it turned to 50. After that, I changed the value of the level to 1 again, but each time after that , when I changed the value to -1, my levels would only increase one or two levels at a time deoending on the monster I kill and I dont get more than a few gems. Can anyone tell me where I went wrong and offer a solution?
*update**
I commented before reading your steps so I could view the steps because it was hidden until I replied to the post, so I'll try your method and see if it works.