DoL Leves

What is the recommendation of running Leves on the DoL classes? For instance, let's say someone is a lvl 30 miner. Is it in their best interest to pick up lvl 25 Leves and up the difficulty to +4 or is it better to pick up lvl 30 Leves and leave it +0 difficulty. The reason I am asking is it seems the only way to maximize xp is to not grind on items that are higher level due to the lower gathering rate.

Even picking up a lvl 25 leve and jacking up the difficulty to +4, some of the items were lvl 32. With all lvl 30 DoL gear, the gathering rate was like 66% or something. When using the +gathering rate abilities, I was still missing a lot. I was surprised to see the leve wanting me to gather a lvl 32 item when the leve was rated at lvl 29. This was one of the Leves that is based on a rating (I.e. +25% xp bonus for getting 320 or more points).

Any feedback is welcomed.

I can tell you thereare level 30 leve in Casa Del Sol (or howevers its spelled). There are 4 different leves, one of them with "Kidd" in the name has you gather off 8 nodes. Its the only leve that gives you a bonus based on how well you do. If you have good gear and food and use the +15% to gather on 7/8 nodes you should be able to get the 25% bonus repeatedly. However, the only level range I was able to do this consistently was My lvl -2. I.E. If you are level 32, set it to +0; if you are 35, set it to +3.