The only real context wherein it is acceptable to use the phrase "mostest" is straight away after the words "I love you the". "Bestest" is additionally satisfactory in this context (and no other). This matter has long been lined at Language Log (see below and in this article). In https://financefeeds.com/qubetics-4300-roi-potential-among-the-top-copyright-to-join-for-2025-will-tron-and-cronos-see-such-a-surge/