Is there any answer for my question?

Yes, you can create additional Profiles and have Sync work between multiple Profiles. And to have different add-ons between those Profiles just don't select Add-ons under Sync across all devices in the Profile/s where you don't want add-ons to be synchronized. The actual extensions aren't really saved on the Sync server; they are installed from the official add-ons server was part of the Sync process; either the initial Sync process on a new device or when the user installed a "new" (to that user) on one device and then additional devices connect to Sync. The related data is also sync'd, or not - see comments below.

As far as losing data, just backup your Profile before experimenting with Sync preferences. And backup it up as you go, at each stage. https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles#w_backing-up-your-profile

IMO, sync for Add-ons/extensions is overrated. Many extensions don't synchronize completely and the Add-ons website doesn't have a section for the add-on developer to specify exactly how or what their extension will synchronize. And few developers provide information about exactly which "hidden" (in about:config) preferences need to be toggled on the effect synchronization as complete as what the developer built into their add-on.

I usually run between 40 and 50 extensions per Profile (about 10 to 15 unique to each Profile), and 3 different Profiles . About 18 months ago I built a new PC and for the first time I wanted to use Sync to get those Profiles to the new PC. I wasted many hours over the course of a week or two trying to fix differences between the new PC and the old one every time I found something missing on the new PC that didn't get sync'd over from the old PC. I finally gave up and just copied those 3 Profiles over from the older PC to the new PC. And it's not like I an a new Firefox user or an inexperienced user; started using it two years before it was named Firefox (Aug 2002) and two years before Sync evolved from the original Weave add-on. Plus if an add-on isn't hosted at the official add-ons website it won't get "synchronized", even when the add-on gets installed AND updated from a 3rd party website. And there are many extensions that are hosted by the developer; perfectly acceptable as long as the "rules" are followed - secure HTTPS server, the extension is signed by Mozilla, etc.

So, seems like anyone didn't test that before, so I just logged in to my Firefox account in Firefox Dev Edition & because FDE used separate profile & nothing bad happens during syncing data, so seems like syncing data & using multiple profiles are friends !