segregated witness – Why doesn’t my Taproot transaction builder (buildTaprootTx utilizing @cmdcode/tapscript) work as anticipated?

I wrote the next perform to construct and signal Taproot (P2TR) transactions utilizing @cmdcode/tapscript. My intention is to assist each key-path and script-path spends, and optionally each collectively.

The issue is that it doesn’t work as anticipated:

Script-path spends typically fail to validate (e.g., management block errors, invalid witness, or failed script execution).

Can somebody evaluate my code and level out what’s flawed with my logic or implementation?
I’d particularly admire recommendation on find out how to repair script-path failures and any efficiency enhancements for the key-path case.

import { Handle, Signer, Faucet, Tx } from '@cmdcode/tapscript';

protected buildTaprootTx(
  senderKey: { publicKey: Uint8Array; privateKey: Uint8Array },
  utxos: Array<{ txid: string; vout: quantity; worth: quantity }>,
  recipient: string,
  amountSat: quantity,
  feeSat: quantity,
  mode: 'key' | 'script' | 'each',
  scriptLeaves: Array = [],
  opReturnData?: Uint8Array | string,
  changeAddr?: string
): string {
  // ... (full code as in my gist, see hyperlink beneath)
}

full code

Questions:

• What am I doing flawed, particularly relating to script-path spending?

• Is there a greater technique to construction or optimize the perform for
  efficiency and correctness?

• In the event you spot any apparent bugs or misunderstandings in how I exploit
  Taproot key/script path logic, please level them out.

Any code evaluate, recommendations, or working instance references are extremely appreciated. Thanks!