The NASA Workmanship standards show 100% fill of plated-thru holes as preferred workmanship practice:
"Populated plated through holes (PTH) should exhibit a vertical solder fill of 100%, with a fully formed fillet on the solder side, and evidence of 100% wetting on the component side lead, barrel, and pad."
Acceptable:? " A slight recessing or shrinkback of the solder into the PTH below the solder pad is acceptable, providing the lead and pad exhibit wetting and the shrinkback is slight."
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My old links to the standards no longer work for whatever (hopefully not nefarious) reason, fortunately they are still available: ?
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I know that we are not making space flight hardware, but we may as well take advantage of the hard-won information available and use best practices when practical.
73, Don N2VGU
Donald S Brant Jr