Investigate small-arg logic as in issue #691

Job	Run time
posix (Collect coverage distribution_tests, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, d...	6m 22s
posix (Collect coverage interpolators, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, interp...	28m 10s
posix (Collect coverage quadrature, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, quadrature)	11m 5s
posix (Collect coverage mp, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, mp)	3m 5s
posix (Collect coverage autodiff, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, autodiff)	5m 50s
posix (Collect coverage special_fun, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, special_...	12m 43s
posix (Collect coverage misc, yes, gcc-12, 20, ubuntu-22.04, g++-12-multilib, 64, misc)	8m 5s
	1h 15m 20s

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