Yes, it is possible to move configurations between different models of firewalls. There are some cases, where there will be differences in the configs that must be modified first, such as Interface #s, HA ports, etc,.
There will be some other considerations when taking a config from one platform to a smaller one. The higher-end devices support more objects, zones, policies, routes, tunnels, etc. As long as you're not exceeding the capacity of the smaller device, you should be good.
If you run into any problems, you can edit the .xml config from the larger device, resolve the issue, save the new config, and then import into smaller one.
Good luck!
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