Kidd and law were never that important to story in comparison to Shanks and BB and WG + Navy.
So oda finishing them quick makes sense.
But as of now RA + WG + Ancient kindom + Df lore haven't been properly addressed.
And, then we have shanks and BB - oda won't rush them as he is building them from the beginning.
With so many important characters and plots still left which definitely will require 6-7 years even if oda rush the story so really don't think oda has anytime to take care of other plots.
I agree, unless they are relevant to the plot. For example the Burned Scar Man could be where the Level 6 escapees all flocked to (he recruited them just like BB did). CP0, Gods Knights, Revos, Gorosei, Kong, Im etc probably are all endgame matters. Maybe the Egghead leads to the Underworld because Stussy is present and this leads to the identity and location of the burned man.
Things like this. Egghead alone is tying Vegapunk, Kuma and Kizaru together, so later arcs absolutely will combine groups.