I have a client right now that wants a .psd file with smart objects done (template like)
in GIMP.
I told them that I am more focused on GIMP 2.10 and that there are people on this forum who can do template for them using smart object like in GIMP 3.0.
Since you're already doing templates as I have seen, there's no reason why you can't do this with some pay from fiverr right.
It's just something I don't want to get into right now because of brain power involved hehe.

There are no "smart objects" in Gimp 3... There is non-destructive editing that AFAIK does a bit what the layer effects do on PS.

According to the client they just want a template that does layer effects of gradient shading of some words. But when I open the psd in GIMP it's just white but the preview on windows show gradient shading of the text.

trandoductin: We don't yet support all the PSD features, though now that we have NDE we can start on that. We added support for importing the Color Overlay style as part of a test of the new public filter API. Gradients and other layer effects are hopefully coming after 3.0 when we can really start working on new features again.

The preview shows the "merged" version of the PSD, which merges down all the effects into a single raster image. That's why the gradient is visible.

I don't know I thought I'd post and told the client to sign on here if possible if they want a template done where they can change the text and all the effects automatically update.

yes GIMP 3 can do workflows like that.