For the app to be safely customizable, it would be nice to distinguish different types of tables in the database:

• "core tables": are common to all configurations, and remain always compatible with previous versions (eg, we never drop a column...)
• "modules tables": are instance-specific. For example, tables of nematodes, used only in nematode labs.
• ...

Even better if we later have the possibility to move a "module table" to the set of "core tables".