Window Installation Insulation

We had our windows installed yesterday and today. We had Softlite Imperial LS windows installed. The gaps on the side of the windows were "filled" with a rigid flat piece of foam. On the first window there is only 1 piece of foam and it comes nowhere close to filling in the gap. I questioned the installers about this and asked them about using a minimally expanding foam. They told me that spray foam was no good and that they never use it. They then used 2 pieces of flat foam on the rest of the windows. This filled it in a bit more but it is certainly not air tight.

Four of the windows are in a part of the house I am renovating. As a result, the inside is not caulked because it has not been trimmed yet. What I would like to do is to take out the flat foam pieces and use a minimally expanding foam to fill in the gaps. I have to use some minimally expanding foam on 2 doors that were installed as well, as nothing was put in the gaps around the doors. My question is: Is this a good idea?. Thanks in advance for any advice or insight.

You should not disturb the installation as a result of this.

If you want to, go for it. You can just seal up that gap with sealant as well, but I too, prefer foam.

yes to low expansion foam. read and follow directions.

Absolutely, you should foam the perimeter that you can access. It's far superior to the method your installers used.

And after you fill them with minimal expanding foam, I'd throw the idiots off the job if it were me. Rigid foam, OMG how incompetent can someone be?

Would love to see pics of the rigid foam installed around window. I would make sure they set all the windows right before you foam them in.

i cant imagine anyone using rigid foam. are you sure it wasnt backer rod ?