Complex certificate question
 

I have:

Easa atpl h with ir valid until next december. (Have easa cpl h without the ir)
Faa cpl and ir h

In my corner of the world, trying to rent me a helicopter has proved impossible, unless I am willing to take a flight to the capital of Norway.

Therefore, I figured its time to get a ppl-a (cant be bothered to bridge) to easily build hours.

Question: If I get a ppl-a and an ir-a, will the ir-a make my atpl ir remain valid?
And is this ppl/ir combo possible in the easa system?

Thanks chaps👍