I'm flying a TPAC in J mostly on KE. On the way back, I'll be checking in with DL and flying one segment on DL, but flying KE the rest of the way. Is the baggage allowance the same? I want to check 2 boxes and get them close to the maximum linear dimensions (but they won't be heavy), will this work if they are interlining to KE?

Suppose I exceed dimensions or weight, or want to bring an extra. To whom do I pay the excess baggage fee and will it suffice to bring the boxes on KE as well as DL?

Thanks for any info/suggestions in advance.