I used this tool to count co_const size and numbers.
https://github.com/faster-cpython/tools/pull/6

Target is asyncio in the main branch.

main (b34dd58f):
Total: 31 files; 1,068 code objects; 12,741 lines; 39,208 opcodes; 3,880 total size of co_consts; 738 number of co_consts

LOAD_NONE (https://github.com/python/cpython/pull/28376):
Total: 31 files; 1,068 code objects; 12,741 lines; 39,208 opcodes; 3,617 total size of co_consts; 743 number of co_consts

(b) LOAD_NONE + CO_DOCSTRING (b: https://github.com/methane/cpython/pull/36):
Total: 31 files; 1,068 code objects; 12,741 lines; 39,208 opcodes; 3,272 total size of co_consts; 732 number of co_consts

(d) LOAD_NONE + remove docstring from code (d: https://github.com/methane/cpython/pull/37):
Total: 31 files; 1,068 code objects; 12,741 lines; 39,469 opcodes;  3,255 total size of co_consts; 574 number of co_consts

number of co_consts:
main -> (b) = 738 -> 732 (-6, -0.8%)
(b) -> (d) = 732 -> 574   (-158, -21.6%)

total size of co_consts:
main -> (b) = 3880 -> 3272 (-608, -15.7%)
(b) -> (d) = 3272 -> 3255  (-17, -0.5%)  (*)

(*) It seems tiny difference. But note that code objects for modules and classes will be released after execution. So (d) will have smaller total size of remaining co_consts after execution.

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Another target is SQLAlchemy-1.4.25/lib

main (b34dd58f):
Total: 236 files; 11,802 code objects; 179,284 lines; 372,983 opcodes; 46,091 total size of co_consts; 7,979 number of co_consts

LOAD_NONE (https://github.com/python/cpython/pull/28376):
Total: 236 files; 11,802 code objects; 179,284 lines; 372,983 opcodes; 43,272 total size of co_consts; 7,980 number of co_consts

(b) LOAD_NONE + CO_DOCSTRING (b: https://github.com/methane/cpython/pull/36):
Total: 236 files; 11,802 code objects; 179,284 lines; 372,983 opcodes; 39,599 total size of co_consts; 7,833 number of co_consts

(d) LOAD_NONE + remove docstring from code (d: https://github.com/methane/cpython/pull/37):
Total: 236 files; 11,802 code objects; 179,284 lines; 375,396 opcodes; 39,418 total size of co_consts; 6,526 number of co_consts

number of co_consts:
main -> (b) = 7979 -> 7833 (-146, -1.83%)
(b) -> (d) = 7833 -> 6526   (-1307, -16.7%)

total size of co_consts:
main -> (b) = 46091 -> 39599 (-6492, -14.1%)
(b) -> (d) = 39599 -> 39418  (-141, -0.36%)

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Conclusion: (b) reduces total size of co_consts significantly, and (d) reduces both of total size and number of co_consts significantly.