Longest forced sequence that ends with checkmate and every move is a check What is the longest move sequence that ends with checkmate and every move is a check by both players?
I'm not aware of any resources documenting the specific situation you're asking about. The closest available is probably this page from Tim Krabbé's chess records which documents the longest known series of mutual checks, but not ending in checkmate.

One of the puzzles from the page could end in checkmate via 14.. Qb7# instead of 14...Bxb7+, so this would be an example of a checkmate after 27 consecutive checks. This series of checks could be considered "forced" by the objective of the puzzle.

[Title "G. Leathem, Fairy Chess Review, 1938, 28 Consecutive Checks"]
[FEN "K2kn2r/NP1P1PPP/1PPPnNq1/1Rr1Bb1Q/4R3/8/8/8 w - - 0 1"]

1. c7+ N8xc7+ 2. bxc7+ Nxc7+ 3. dxc7+ Ke7+ 4. g8=N+ Rxg8+ 5. hxg8=N+ Qxg8+ 6. f8=Q+ Qxf8+ 7. Qe8+ Qxe8+ 8. d8=Q+ Qxd8+ 9. c8=N+ Rxc8+ 10. bxc8=N+ Qxc8+ 11. Bb8+ Bxe4+ 12. Nd5+ Bxd5+ 13. Nc6+ Bxc6+ 14. Rb7+ Bxb7 (14...Qxb7#)