TL;DR
Add the ability to mark a logistic request as a mixed rocket load. Multiple items are loaded into the silo and launched together, as if the player had manually loaded the items and pressed the manual launch button.What?
When editing a logistic request from a space platform, add a tick box (off by default) to mark this request as a mixed rocket load.The request has to be verified that it will fit in a single rocket, so the combined weight of all the items must be less than or equal to one ton, or the box cannot be checked. If the request is edited, the mixed load option gets turned off, to be re-verified if and when the player turns it on again. It might be helpful to pop a brief warning that the mixed load option has been turned off, especially if the request is edited from planet side rather than from the platform.
The player can select which planet to use as the source, however the source planet is applied to all items in the request. The minimum launch payload is not applicable, overridden by the amount set in the request that has been verified to fit.
When the platform arrives at the source planet, if any of the items in the request are missing from the platform, the platform requests the mixed load (not a partial load to top up what is missing, the entire mixed load comes as a unit). If there is a silo not marked for automatic responses, and it already contains the requested items, it will be launched to satisfy the request. Otherwise, if enough items are available in the logistic network to satisfy the request, they are requested into the silo, and launched to the platform.
Why?
A mixed rocket load serves the occasional need to send multiple items in small quantities, unlike the regular bulk deliveries of things like science or bioflux. I could see defining a request like the Planet Starter Pack containing solar panels, power poles, miners, furnaces, assemblers and inserters. Arrive at a new planet, put down the landing pad and set the starter pack request, so all the starting items are dropped automatically, no more clicking on items in the hub to get started.It overcomes the current limitation of only being allowed to send varying quantities of a single item in an automatic launch.
It overcomes the current limitation of not being able to automate something that you can do manually.