Would it have been more advantageous for Lee Hwa-young if he had confessed, even falsely?

Yes, from a purely judicial and practical standpoint, it would have been much more advantageous for former Vice Governor Lee Hwa-young personally to significantly reduce his sentence.
In our judicial system, even if it is a "false confession" that is not true, the legal benefits a defendant can obtain by admitting to the crime in line with the prosecution's indictment and cooperating with the investigation are very clear. Specifically, it would have been advantageous for him for the following reasons:
1. The possibility of ending with a "light sentence" like former Chairman Kim Seong-tae
The case of the financier Kim Seong-tae:
Former Ssangbangwool Chairman Kim Seong-tae, a key figure who directly provided the funds to North Korea, actively testified regarding Governor Lee Jae-myung's involvement from the early stages of the investigation. As a result, despite the heavy nature of the crimes—smuggling large amounts of foreign currency and remitting funds to North Korea—he was sentenced to a relatively light sentence of 2 years and 6 months in prison in the first instance.
2. Shifting from "main perpetrator (the trunk)" to "working-level official following orders (the feather)"
Because former Vice Governor Lee denied the charges until the end, the court viewed him as a "co-principal (main perpetrator)" who planned and led the North Korean remittances along with Chairman Kim Seong-tae and handed down a severe punishment.



If he had confessed to following the Governor's instructions, he would have become a "subordinate working-level official who had no choice but to act according to the Governor's orders and the local government's North Korea policy stance," thereby shifting the weight of the crime and responsibility (sentencing) to Governor Lee Jae-myung, which could have significantly reduced his own sentence.
Reasons and risks for not being able to confess (or retracting the confession)
However, maintaining a "false confession" also presented fatal risks that were difficult for former Vice Governor Lee to handle.
Risk of punishment for perjury and false accusation

Political ruin and the "traitor" frame

The process of retracting statements
Summary
As a result, former Vice Governor Lee Hwa-young struggled between the "practical benefit (advantage) of significantly reducing his sentence through confession" and the "justification of extending his political life by maintaining loyalty," and ultimately chose the latter.
However, as the heavy sentence (7 years and 8 months in prison) was finalized by the judiciary, he ultimately missed the practical opportunity for a sentence reduction and ended up taking the full blame, which is why he is currently expressing resentment and anger toward President Lee Jae-myung and the party, saying, "I am the only one left abandoned in a cold prison for five years," and is demanding parole.
This is an answer from Google Gemini.