Prometheus queries result are transformed the same way for timeseries and heat_map data format

We are using prometheus to collect some state in metrics and we want to display only the state change in grafana. Prometheus queries are pretty simple and convenient to handle that ( state - state offset 1m !=0 - data are scraped every min ). Prometheus in this case return only value when the state is changing which is also allowing to reduce the load of rendering such data.

When using this kind of queries in a table panel , we are facing a lot of problem.
The data transformation which is applied to the result insert the missing timestamp leading to inconsistent vizualisation ( a lots of rows with empty values ) .

After digging a bit into the code (and especially the result_transformer : ) , i’ve realize that the code is the same for heatmap and for timeseries with matrix result from prometheus.

From my point of view both should have different behavior:
The heatmap data format should fill the gap as we want to see the full time period.
The timeseries data format should only return the data point of the queries and should not insert any missing values as we want the result of the timeseries queries.

We have tried to use the table format , but due to a lack of formatting capabilities this is not an option.

Any thought ? workaround ?
Thanks in advance