It will get you through the first few levels gear wise, but I would NOT be using 510 gear anywhere above 84 at most based on past experience. You will also probably get quest rewards along the way for your desired job, so you probably don't need to grind dungeons (much) and/or buy gear for it, which I'm assuming is PLD based on your post. Either way the same would apply for any job, but more so for healers and tanks for everyone's benefit. They should, ideally, stay in tip top shape on the way to max level as best as they can. But if you buy the Cryptlurker gear which will be purchasable for poetics with Endwalker, you'll be good until around 85-86 ish based on what they've done in the past. Personally, I think it's worth the poetic farm for the quick boost.