Sit me up

My 15 week old is too big for his boppy lounger and his swing. He hasn’t been weighted in 3 weeks but he was 15 lbs back then. He will get weighted in 2 weeks at his 4 month appt. we think he’s 18-20 pounds. the sit me up has a max weight capacity of 25 lbs. do you all think it’s still worth getting at this point? Will he even fit in it? Anyone using something else that baby can sit on while i do stuff around the house? Its super tiring holding him all day long. Even my husband’s arms hurt lol We have a jumperoo but i think its too early for that still. TIA!!