I have done it without any compatibility problems. However, it seemed to alter the sheen, and I did not like the results. I find decals adhere so well to Alclad that I don't need to seal them. As far as weathering, Aclad is pretty stable and tough, so I just weather over the stuff.
The one thing that DOES kill Alclad is CA accelerator! I had a little part fall off a model I had already done the Aclad on. After gluing the part back on, I put a daub of accelerator on it to speed the cure. Bad idea! It left a gray stain there. After that, if I had to do any gluing over or near Alclad, I let it cure naturally.