Remove sanity checks about update formulae once determined appropriate

[ppebay]

Following #611, the debug verification is still performed, by comparing the update vs. full recompute results; until we convince ourselves fully that the update formulae are correctly implemented (and no theoretical errors were made in the paper either...). At this point, validation sanity checks could be safely removed.

[ppebay]

This:

is why removing the sanity check may still be premature (related to PR #612 where the memory error was serendipitously detected with a configuration non even feasible to begin with and therefore not part of the test harness)