Allow more flexibility to mystery gift

So I just had a match and my team isn't doing too well (coz of jungler and me top xD) and our adc was starting to get quite salty. But our mid laner kept positive and doused the adc's flame. He explained that beginners start from somewhere and making mistakes is how one learns.

We lost the match but before I was able to tell him that we needed more people like him in the community, he left the lobby. So I wanted to send him a mystery gift but the message options were only limited to "GG, HAHAHA!, well played, and a few other presets but no option for a custom message.

Sooooo....maybe riot could tweak this? xD or maybe there is some other alternatives?

p.s. I don't wish to add him as a friend just to thank him