[bug] Pipeline editor hanging with mutiple 'plugin' nodes #60

What happened?

I have multiple pipelines that have a high number of plugin nodes (5+) within the effects chain, and whenever I start the app and open the pipeline, the app will hang for a very long time, usually 1-2 minutes. During this period the plugin nodes have the selected plugin listed as 'Scanning...', and then once the app becomes responsive they are filled with the name of the actual plugin I selected. I belive this is related to the latency when adding a single new plugin node, as whenever I add one the app will become unresponsive for 10-20 seconds while it scans for plugins. Im guesssing when I open the pipeline, rather than load the specific plugin that is stored in the node, it is first re-scanning, then loading the correct plugin, and additionally it is re-scanning for each individual plugin node. I would think that the plugin nodes that already have plugins loaded would not re-scan when loading the pipeline editor, and maybe the list of plugins could be cached and only re-scanned when directly clicking the re-scan button in the dropdown.

This issue doesn't break anything outright, but definitley impacts usability for more serious use cases with plugins and makes it hard to add plugin nodes on the fly/quickly.

Steps to reproduce

1. Open splitwave
2. Create pipeline
3. Add large number of plugin nodes and select plugins on them, seems to scale linearly, I saw 2 minutes with 6 pipeline nodes, although I have hundreds of plugins.
4. Restart splitwave and open the pipeline again

Expected behavior

If the slowdown when scanning for plugins cant be avoided, I would expect for the noodes which I have already selected a plugin for to not re-scan when opening the pipeline again, and I would also expect the slowdown to scan to only happen the first time I added a plugin node and the list would be cached so I can add more plugin nodes without the scan slowdown happening every time. I would prefer if the re-scan only happened when I clicked the re-scan button, as my list of plugins changes infrequently compared to how often Im adding a new node.

App version

1.4.0

Operating system

macOS

OS version

Sonoma 14.6.1

Additional context

No response