As one of the problems is the speed of comms link when using mobile on 3G or 4G or Bad Wifi access, I would like to be able to restrict the transfer of records from servet to the columns really used in the Powerapps Program. This will lead to smaller data to transfer then better response time.
To be coherent with the Poweraps philisosophy I suggest that for example with an SQL server Query when used fields names are obviously known because they are used within a formula, only thoses would be retrieved by the generated SQL Query. This would be Transparent for the PowerUser and would be I think a good solution.
If not possible a list of retieved columns could be added in filter startement, note that even if one field is requested by Lookup, in fact all fields are retrieved, should be here a list of field to retrieve and restrict to it.