What does it mean when a character's armor has the "Same Bonus In Use" label?

I imagine it is the obvious fact that the items give the same bonus. But does it boost that specific bonus or the armor pieces in general in any way?

For example I am wearing a Legendary Imperial Seal and Legendary Dark Rosary and I am not seeing any visible change in their stats when the label is there versus not.

The Same Bonus In Use applies to equipment with the same rarity, so you would see it often with all the legendary items you get at rarity 50. This applies a small boost to the stats of those items (not sure how small), and would be impossible to tell without doing the math yourself.

Personally i'm too lazy to add it up myself, but the previous games did the same thing (there may be some exceptions, but i started with D3). Like in Disgaea 4, if you wanted to max your stats, not only would you need R40 equipment, you would also want them to be the same rarity (I.E. Legendary Rarity 10 on all items) for that bonus as well, as well as a few other things to max out stats.

Keep in mind, I've checked some of those items and the higher the rarity, the better the stats are on the item in Disgaea 5. Also it seems a lot of legendary items are rarity 50.

Hope this helps, if i missed anything i'll edit my post.

restarted, atm about the best i got is feather token, so 109 in all stats, makes a good foil, on maid, who has mostly even stat boosts, having sp 90%, res and hit at 105%, rest at 100%.

equipping the all stat things for ease of measuring, equipping imperial seal as a base, the +109 feather token gives 113, so with 7 and 109 together only gives 4 extra points, probably all from FT. 3.3% seemingly

devil ring at 49, plus feather token is 114, giving slightly more.still like 3%

all three together is 119, 5.7% ish.

weapon too is 124 124 on weapon not increasing it 0 + 7 + 49 + 109 gives a bonus of 15. evenly divides to 11%.

using speed on weapon, feather token is saying 129 now. 119 + 7 + 49 +109 gives a bonus of 20, 14.2%

so, at a guess, the same bonus might add like 3% ish per same bonus, improving a bit for multiple same bonuses.

would be better if i had higher accessories but atm, this is the best i got.doesn't help that the imperial seal is probably getting shit for dick to actual stat gains from it. though amusingly since the bonuses show up in the changed stat thing, with the +7 bonuses i get from my all 4 gear at the end, if i'm equipping the seal last, it looks like it goes from +7 to +14. its still just seven from imperial seal, but since the other stuff's bonus stats come on, it just adds it to this total.