[Bug]: Smart Transactions - Legacy transactions (type 0x0) are converted in type 0x2 when routed as a smart transaction

[seaona]

Describe the bug

Whenever I am sending a type 0x0 transaction, I can see how the gas values are the ones corresponding to the type 0x0 tx. However, if I have the Smart Transaction setting enabled, that transaction will be sent as a type 0x2 without notice.

Expected behavior

If Smart Transactions are only supporting type 0x2, we should not convert legacy tx to type 0x2 tx without notice

• either we display a warning to the user
• or directly display the EIP1559 tx screen with the corresponding gas

Screenshots/Recordings

https://github.com/MetaMask/metamask-extension/assets/54408225/9eeeb103-79a0-4724-a378-33798e5ed04d

See how displayed gas values are legacy ones

Steps to reproduce

1. Enable Smart Transactions
2. Select Sepolia
3. Go to the test dapp
4. Trigger a Legacy tx
5. See how gas corresponds to the legacy tx view
6. Submit the tx
7. Go to Etherscan
8. See how the tx is no type 0x2 with the EIP1559 gas

Error messages or log output

No response

Version

11.16.4 prod

Build type

None

Browser

Chrome

Operating system

Linux

Hardware wallet

No response

Additional context

No response

Severity

No response

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had recent activity in the last 90 days. It will be closed in 45 days if there is no further activity. The MetaMask team intends on reviewing this issue before close, and removing the stale label if it is still a bug. We welcome new comments on this issue. We do not intend on closing issues if they report bugs that are still reproducible. Thank you for your contributions.

[klejeune]

This feature is not currently supported. Closing the ticket.