This doesn't work out with the PC version changes for one specific reason: rare enemies scale massively with BR.You can still fight a ton of battles, just make sure you fight several enemy groups at once so that your leveling and skill development can keep pace with the enemy scaling. Once you're far enough into the game that you have a fairly ideal party together, chain some mobs and go nuts.
It doesn't matter that much for the critical path (since those are all at a static BR), but a lot of optional stuff and just getting through some areas will be difficult to impossible if you do too much fighting before you have your "final" party composition (which means you have to wait until Disc 2 before you can really even play the game).