Writing a DIMR model fails (or takes a very long time) when the number of laterals is large

[RuudHurkmans]

Describe the bug
When a large set of laterals is added to an ExtModel, DIMR.save() iterates over the laterals, writing the entire .BC file for every lateral.

testdata_laterals.zip

To Reproduce

• Run the attached script, which reads data from the also attached GPKG. The Hydrolib is needed.
• it builds a dflowfm-model from branches and laterals.
• The script gets stuck on the 'dimr.save()' line because it writes the .bc file over and over again.

A workaround is to add only the first lateral to the ExtModel, and then write the other laterals afterwards to the existing .ext-file.

Expected behavior
I would expect dimr to write the .ext and .bc file once.

Version info (please complete the following information):

• OS: Windows 11
• Hydrolib 0.3.1, Hydrolib-core 0.8.0

Additional context
Add any other context about the problem here.

[arthurvd]

Thanks Ruud, clear explanation, we'll try and look into it.