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

I wrote the next operate 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 overview my code and level out what’s flawed with my logic or implementation?
I’d particularly respect recommendation on tips on how to repair script-path failures and any efficiency enhancements for the key-path case.

import { Deal with, 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 under)
}

full code

Questions:

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

• Is there a greater method to construction or optimize the operate for
  efficiency and correctness?

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

Any code overview, ideas, or working instance references are extremely appreciated. Thanks!