Yeah that's a really annoying issue I've encountered many times before. Screenshake not working without unbounded scrolling is really annoying.
The solution I've been using recently is a little effect I made called Jitter. This does not work with webGPU so you'll have to disable that if you want to use it. construct.net/en/make-games/addons/1643/jitter
1. Apply that jitter effect to the entire layout (disable it)
2. Enable it briefly for the screenshake and tweak the values to your liking
3. Optional: Use a tween to decrease the magnitude over time to emulate the behavior from the "scroll to" screenshake effect.
It kinda smears the edges of the screen which may not be ideal but it's really not noticable imo.