I tried to import a character from Gacha unlocked to Gacha luminal the same that way you did and it worked!
I made a character in Gacha unlocked, Exported the Code and imported it to Gacha luminal, it Worked, but strangely, on the first attempt at importing the character, the color of the shirt was black, but the color was supposed to be a color similar to peach(the color of the shirt had same color as the skin), and then, on the second attempt at importing the character, the color of the shirt was back to normal, I imported the character a few more times, but the glitch of the black shirt never happened again!
Though I have not tested if importing characters from various mods to Gacha luminal works properly, I haven't found any major issues while importing a character form Gacha unlocked to Gacha luminal.
