What are you trying to achieve?

In the SDK spec on DefaultAggregation, it suggests that for AsynchronousCounter a default SumAggregation is used for aggregation.

Instrument Kind	Selected Aggregation
Counter	Sum Aggregation
Asynchronous Counter	Sum Aggregation
UpDownCounter	Sum Aggregation
Asynchrounous UpDownCounter	Sum Aggregation
Asynchronous Gauge	Last Value Aggregation
Histogram	Histogram Aggregation

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#default-aggregation

When implementing the SumAggregation for the asynchronous counter, I found that in the SumAggregation:

SumAggregation informs the SDK to collect:
The arithmetic sum of Measurement values.
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/sdk.md#sum-aggregation

Whilst to the asynchronous counter, the Measurement values mean:

The callback function is responsible for reporting the Measurements.
Note: Unlike Counter.Add() which takes the increment/delta value, the callback function reports the absolute value of the counter.
https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/api.md#asynchronous-counter

That's been said, the Measurement values in asynchronous counters are absolute values and not increments. To SumAggregation, the arithmetic sum of Measurement values of asynchronous counters doesn't seem to be meaningful.

This issue also applies to the Asynchronous UpDownCounter.