Hi joenovo123,
When I was a TKI at one of the integrated schools there were a few of students who due to various reasons once they had finished their ATPLs (and that's the key bit) quit the integrated training & went modular. Your ATPL exams will exempt you from the PPL exams once you start on the modular route & the exam credits belong to you not the school. So it is perfectly possible, though your current flight school might not like it due loss of revenue - check your training agreement with a fine tooth comb there could be exit penalties. No potential employer is going to give a damn about you switching at such an early stage & unless you tell them they are unlikely to know (but don't mislead).
In summary it's possible but you might have to negotiate some obstacles, make sure your training records are transferred to your new FTO. This was the case a couple of years ago, I doubt it's changed but it would be wise to check with the CAA before jumping ship.