I would suggest to more expandable turtle tools upgrade.

For example, turtle tool flow can be splitted in this steps:

1. Selecting blocks to break
2. Generate tool to break blocks
3. Block breaking

• Check if block suitable for break (extra callback)
• Check if breaking could continue (for example, fluid check)
• Block breaking
• Process drop

I guess, most of modders would be interesting in changing everything expect actually block breaking.

So, for example, each of this steps, expect block breaking, could be a part of API.

Here is my crude example, of how this can be: https://github.com/SirEdvin/ProgressivePeripherals/blob/1.16/src/main/java/site/siredvin/progressiveperipherals/integrations/computercraft/turtles/base/TurtleDigTool.java

Not perfect at all, but some idea show be ... visible?