If you say that something would not go amiss or would not come amiss, you mean that it would be pleasant and useful.

What does do not go amiss mean?

British. : to be welcome, proper, helpful or appropriate A little more encouragement would not come/go amiss.

What does it mean for something to go amiss?

(Entry 1 of 2) 1a : in a mistaken way : wrongly If you think he is guilty, you judge amiss. b : astray Something had gone amiss. 2 : in a faulty way : imperfectly practiced more so as not to play the piece amiss.