Thanks so much! Yeah you're right, the game won't run in GBARunner2 unfortunately. This is out of our control but I believe GBARunner3 is in the works which should fix it. :)
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Yes - you can mod your DSi by following dsi.cfw.guide, and you can get unstable versions of GBARunner3 from here.
I tried it a few months ago but the game still didn't run very well sadly... I don't remember exactly how to set it up but the folks on the DS(i) Mode Hacking Discord may be able to help if you have more questions.