Even Wamatangi is preparing to jump into UDA. It's his loss if he quit UDA - the most popular party in Kiambu. It will be gigantic Ngirici like blunder. Many are afraid of UDA nomination - Jungle saw dust in Jubilee nomination - so he must be scared.
Let him run as independent but he will struggle in Upper Kiambu(Dagoretti-Kikuyu-Lari-Kiambaa-Githunguri) - he will fly in lower kiambu (Gatundu-Juja-Ruiru-Thika)
He needs UDA for the upper Kiambu otherwise it's likely either Wamatangi or even Waitutu will carry it.