Would be nice if when deconstructing, the mod could check the type of pipe connected to the miner and use the same type as a replacement.

For example, the mod could check whether a Krastorio steel pipe is connected (or a steel underground pipe) and in that case place steel pipes instead.

This would be rather annoying to implement, because it would have to search the entire line of miners to find one with a pipe connected. What should it do if the same row of miners has more that one type of pipe already? If anything, I would have it search the nearest logistic network to see what kind of pipe is available there. But that still seems like it would be unpredictable and annoying to the player. Is the global mod setting to set the type of pipe to use so inconvenient? You can always change the ghost types with an upgrade planner to match what you have available.

(Before changing the pipe selection behavior, I have to fix the fact that it won't build pipes to other ghost pipes if they haven't been placed yet.)

Is the global mod setting to set the type of pipe to use so inconvenient?

Well, I have a case while playing Space Exploration + Crastorio where some of my outposts only have regular pipes in the inventory and other outposts have only steel pipes 😅 So basically my patches break on the newer outposts after automatic deconstruction.

What should it do if the same row of miners has more that one type of pipe already?

Just grab the first one you find. If there are multiple types on the patch, most likely both are available for placement.

If anything, I would have it search the nearest logistic network to see what kind of pipe is available there.

This sounds like a nice solution. Miners usually don't require a lot of fluid throughput unless they are heavily modded. If you want to step it up a notch, you can calculate the throughput needed for the miners and then select the pipe of the lowest quality that can support that throughput and is available in the network 😂 Sounds tricky though.

I think I will not touch this feature for the foreseeable future. If you would like to try writing it yourself and make a pull request, I'll be happy to take a look. (This mod is a team effort at this point!) You can also disable the removal of fluid miners entirely, so that your mining patches are not interrupted by unavailable ghost pipes.