Hi terramir here,
I've been on the Reprap forums for 7+ years, but I just recently started using cura.
But I am quite well versed in the mechanics of 3d printing. one of the most important things is to get the first layer to stick!
also mechanically it is really not sound to print the same pattern layer by layer the same way.
But back to the first layer in concentric patterns it would be better for the "stick to bedness" to print the concentric pattern on the 1st layer from the outside in.
This way it will stick to the filament from the outer layer in longer runs and also in has more surface area to hold on to the bed.
also then printing the second layer from the inside out will alleviate any holes that might have shown up on the first layer (it happens especially with pet-g on blue tape)
also an option to just print the bottom and top layers concentric and the other solid layers as lines preferably each layer at a different angle will give the part more strength.
an option to do two layers as concentric on the bottom as well as top with two check boxes would be a good feature. (for cosmetic reasons in this case but mostly on the bottom to hide holes)
Sorry this is so long, but yeah there is a reason to do only concentric patterns But this is really only for transparent filaments a check box to do that would be good for those occasions and a check box (by default) to alternate patterns from outside 1st to inside first would be best.
BTW using lines on the 1st top layer is better anyway (unless using transparent), because the 1st layer is sort of a bridge over the infill.
BTW the mechanical soundness also is valid for the non-solid infill the infill should alternate in the angle it is printed at because that does give the part a tiny bit more overall strength.
But on the solid shell this is far more important.
These suggestions will reduce completely failed prints to slightly cosmetically challenged prints, also printing from the outside in on the first layer might just help prints stick far better.
terramir