I faced the same issues with integrating multiple packages and handling minting manually. To simplify the workflow, I built a smart contract and then exposed it through a SDK and a widget that handle all interactions with SPL tokens automatically. Everything is open source under solmint.net and https://mintme.dev — you can mint, revoke authorities, and manage tokens without dealing with low-level integration errors.

Check this video I did https://www.youtube.com/watch?v=9Fyg-SO5ULo&t=247s

npm i mintme-widget

<MintmeWidget 
  endpoint="https://mainnet.helius-rpc.com/?api-key=your-key"
  cluster="mainnet-beta"
  pinataConfig={{
    apiKey: "your-pinata-jwt-token",
    gateway: "your-gateway.com"
  }}
  partnerWallet="your-wallet-here"
  partnerAmount={0}
  defaultTheme="light"
  options={{
    showCredit: true
  }}
  className="my-custom-styles"
/>

Or you can check mitnme-sdk (https://github.com/mintme-dev/mintme-sdk)