Very grateful for all help with these clues please.
13dn: “Poisonous plant in a way welcome - almost blessed (10).”
17dn: “Hear about double celebration, arriving in force for one returning (3,4,2).”
20ac: “Welshman taking cruise after year in the country (5,5).”
28ac: “Quietly detests being involved in key software trial (5-4).”