I would honeslty pass on fiddling with the wallet file unless 100% necessary.
You can always work on a backup rather than the original wallet.dat file.
Is there any problems at all if I just keep the legacy format? as far as I know, the only issue one would encounter was that there is a limit of addresses you can generate in non-HD wallets before you needed to backup:
In the future versions, yes.
In future versions of Bitcoin Core, you wont be able to load old bdb wallet.dat files without upgrading it first into sqlite.
Here's the proposed timeline with checklist of the implemented parts:
https://github.com/bitcoin/bitcoin/issues/20160