If I'm not mistaken, most of this is identical to the test before (and I think also the one in the other file?). I think it's worth to extract it to a helper function to avoid duplicating code and make it easier to maintain.

I think the only differences are

		changeKeypath := append(append([]uint32{}, keypathAccount...), 1, 0)
		inputKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

and

		_, inputPkScript := multisigP2WSH(threshold, xpubs, false, 0)

Which are only used later and could be defined closer to where they are needed.

Which one exactly? The one before it tests BTCAddress, not BTCSign. The other one is BTCSignPSBT, and creating the PSBT is similar but still quite different.

It seems to me that lines 1094 to 1129 are identical to lines 996 to 1028, with the exception of the creation of this vars:

		changeKeypath := append(append([]uint32{}, keypathAccount...), 1, 0)

		inputKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)


		_, inputPkScript := multisigP2WSH(threshold, xpubs, false, 0)

And on the other one:

		receiveKeypath := append(append([]uint32{}, keypathAccount...), 0, 0)

Which are not used within those blocks and can be left out.

And the same for the other file, I believe all of this code is shared between all three tests:

		t.Helper()

		coin := messages.BTCCoin_BTC

		keypathAccount := []uint32{
			48 + hardenedKeyStart,
			0 + hardenedKeyStart,
			0 + hardenedKeyStart,
			2 + hardenedKeyStart,
		}


	ourXPub, err := device.BTCXPub(coin, keypathAccount, messages.BTCPubRequest_XPUB, false)
		require.NoError(t, err)

		xpubs := []string{
			ourXPub,
			"xpub6Esa6esRHkbuXtbdDKqu3uWjQ1GpK39WW2hxbUAN4L3TxrwDyghEwBtUYZ8uK8LZh3tJ3pjWEpxng9tjfo7RT9BaZKV2T3EPvmZ6N1LgSdj",
			"xpub6FJ6FAAFUzuWQAKyT98Ngs6UwsoPfPCdmepqX2aLLPT54M85ARsWzPciFd49foStMwhWgfiHP6PnMgPrWLrBJpUHgqw8vZPd5ov8uSfW2vo",
		}
		ourXPubIndex := uint32(0)
		threshold := 1

		scriptConfig, err := NewBTCScriptConfigMultisig(uint32(threshold), xpubs, ourXPubIndex)
		require.NoError(t, err)

And can be extracted

Added commit, created by deepseek 🤓