How to make a splitable pcb joint with signals for fabtests?

[picatostas]

I am not sure if I named it correctly but basically I need to split my pcb due to mechanical-space constrains. But I would like to leave
the signals through for factory testing. I would use mouse bites in a normal scenario if there where no tracks but I don't know what are
best practices for doing it when you need tracks through.
For the time being my approach has been placing vias across the desired breakline. The signals are Power, gnd and some enable signals.
And routed the interconnected signals in the inner layer. I am using KiCAD, for reference.

[Kasper]

Yes you can route traces between mousebites. Dave shows it in
EEVblog #552 - DFM Automated PCB Panel Testing

I tried it once with cheap PCBs from JLC and it worked well. 

You probably don't want to route different nets on different layers ontop of eachother due to risk of shorting.

I think another option is to route traces on internal layers and v-score the outer layers but I'm not really familiar with that.

[Styno]

I think another option is to route traces on internal layers and v-score the outer layers but I'm not really familiar with that.

On a generic 4-layer board there is a thick core and the inner copper layers are very close to the outer, just separated by thin prepreg. V-scoring would probably score the inner copper layers as well.

[Gribo]

Don't use normal plated vias, use non-plated drill holes (obviously, don't drill the traces), you will get a cleaner break this way. Also, try to use traces either on top or bottom layer and not on the internal layers, as others said, you don't want internal shorts.