Sorry for missing this before.
You can tone down some of the systems that are in place that attempt to keep things running smoothly, which is why fragments are removed. First, you can turn off the budget with Home > Settings > Performance > Dynamic Budget.
Then you can also set Home > Settings > Simulation Performance to a higher setting, which allows more fragments to be created and stick around. If you'd like, you can set this to Custom then expand it with the caret to expose "Max Non-attracting Bodies" -- this is what budgets how many fragments are allowed to stick around.
We'd like to make some significant improvements to our budgeting system, and we also will hopefully have some physics changes in the near future that will help with performance on a whole (which in turn would help keep fragments around longer).