Reply to Super clingy 3 year old just before new baby

My two and four year old love their baby sister dearly, since the first night. But I did notice my 2 year old regress a lot and has been acting out a lot more as I assume he desires more quality attention from me. What has helped, is having him be as involved as possible with his baby sister. When she cries, I tell him to check on her and when he makes her smile or stop crying, he gets lots of praise. He has always been extra clingy and still is. There are some days the baby starts crying and he’s in a bad mood and will cling to me so I can’t tend to the baby, but I always explain to him that I will hang out with him after I help baby sister, or we can go get her together and I can hold them both on the couch, cause mommy has two arms