I set the carpet rule clericsFarmWarts to true, and spawn in a villager next to a brewing stand and a patch of soul sand with fully grown nether wart. The villager converts to a cleric, and I am able to toss netherwart items to him which he can pick up. However, he stands there like a dumbass and doesn't harvest the fully grown netherwart, nor does he plant the netherwart that he's been given. I tested this by turning on the daylight cycle and then tick warping for a full day.

Going to close as it's been a long while since it was opened and it seems to be working for me here.

If it's still an issue though please comment or open a new one!