A rested open circuit cell voltage on an LFP cell above 3.43v is fully charged.
Charging until current taper off with an absorb voltage of 3.45v-3.65v will create a layer surface charge mostly in the negative graphite layer of cell. The charging overpotential voltage rise caused by charging current is traded for this surface charge when charging current tapers off.
This surface charge voltage has no significant capacity to cell. It amounts to about 0.01% of cell AH rating.
It will bleed off on its own. Depending on cell, it may take a few hours to a few days to bleed off on its own with no load placed on cell. You can put a load on cell, like one amp for 60 seconds, and it will bleed off most of the surface charge quickly, after which cell will settle down to 3.43-3.50v of rested open circuit voltage.
Many folks see this voltage drop after top balancing to 3.65v, with different cells showing between 3.45v and 3.65v and incorrectly think the cells are not balanced. If they stay above 3.43v open circuit voltage, they are fully charged and SoC balanced.