As of now MCS uses long double as an internal data for results of avg() and sum() for numerical data types columns except wide-decimal.
This approach imposes a number of limitations, e.g. we can not safely join on the aggregates results being a float number. Presumably long double math operations are slower comparing to int128.
This gets us to the point of replacing long double with wide-decimal as a result of avg() and sum() for all integer data types. This causes a wide consequences that covers lots of facilities of the code. The full list can be obtained by search for LONGDOUBLE in the repo.