I think I have a work-around using logarithm rules:
log2(A) + log2(B) = log2(A*B)
2^log2(A) = A
So I can get the product of the values using sum() aggregation and the logbase() and pow() math functions:
log_L = log2(L)
sum_log_L = sum(log_L)
prod_L = 2^sum_log_L