change keyboard assignment

Trying to find a method to change the key assignment. There is a key combination with “shift” when selecting mass
items, I was wondering if I could change it to “ctrl”.

I guess you refer to multi-selection (screen capture below) or select all? Select all is currently bound to CTRL + A, cf. demo. As far as I am aware SHIFT + A is not bound to anything at the moment

capture.zLjYBo_optimized

I mean multi-selection. The only thing I found was this: bpmn-js/BpmnKeyboardBindings.js at develop · bpmn-io/bpmn-js · GitHub

but it is not clear what the method trigger is called for my case

There is an open bug that prevents CTRL + click from working, cf. After 8.0, I can't use ctrl and the left mouse button to select multiple nodes, it is possible before 8.0 · Issue #1475 · bpmn-io/bpmn-js · GitHub.