A work order to get 5/10 logs of each sapling would be nice to have

I'm including that in the next update, which should be in a few minutes to a couple of hours. The mod update will not be compatible with existing worlds, but the work order can be modified for previous versions. There are new saplings in the update, just delete those from the new work order(s) if you want to use them for existing worlds.

Would it be possible to process saplings for fruits instead of logs?

There are three issues with that:
The fruits are already produced when the saplings are harvested, so giving them when processed is redundant. The sapling plant item represents the trunk of the sapling. It seems odd that any fruits would be left on it after harvesting.

If the sapling isn't processed into logs, how would the wood be obtained? Besides being a source of charcoal, many players want varieties of wood for extra material colors to build with.

Many trees don't produce fruits and are just for wood. The way it works now makes sapling processing consistent and the results predictable. Making the saplings produce fruits instead of or in addition to logs would gum up the existing production lines many players are using.