Would it be possible to consider adding Forza Horizon 1 back to the microsoft store?

It was removed due to licences expiring. Those licences will not be renewed. The only option you have is to purchase a physical copy of the game.

Forza Horizon 5 does NOT have any announced or planned cross-progression from Forza Horizon 4. Aside from Forza Horizon 1 (which did had loyalty rewards for Forza Motorsport titles), there has never been cross-progression for Forza Horizon titles. You always had to start fresh with each game.

And about Forza Horizon 4: the lack of possibility to use the same save between Steam and Microsoft Store comes from the technical point of the each game. Both use a wholly different methods of saving which is far too much work to make them co-operate, ESPECIALLY considering that Forza Horizon 4 is way past its' prime.

OK, is it possible to bring Forza Horizon 3 all add-ons except the base game in Microsoft store?

Forza Horizon 3 Blizzard Mountain | Xbox

Forza Horizon 3 Hot Wheels | Xbox

Hi justin007rules,

Thanks for your post! I see you've mentioned the load taken on your processor from the game, to make sure that your hardware specifications meet standard for Forza Horizon 4, check out the game on the store under the System Requirements tab:

Forza Horizon 4 - Microsoft Store.

I hope this information helps.