Depends on what type of shooting you do...
In general...
I'd skip the red dot/magnifier combo and go with a traditional magnified optic. Some folks find use for them but the guys I personally know have tossed magnifiers in the parts box. And if the prime objective is to please older eyes forget the 1x red dot altogether.
If sitting on yer can at a bench precision shooting at paper... get all the magnification you like. Higher magnification may not help a lot but it won't hurt anything. However, higher magnification is very useful for finding those pesky shotgun hulls taking partial cover behind rocks and weeds. I use a fixed 16x on one my .22s for that reason. Them pesky shotgun hulls can't hide from me at 100yds!

Some guys like to use their rifle scope like a spotting scope to see bullet holes in paper targets at 100yds. You won't be able to do that with magnification much less than 12x.
If holding the gun in yer hands, magnification beyond 4x isn't much help. It just magnifies your movement and makes shooting more tentative and less pleasant. Low power fixed magnification and 1-4x variable scopes are ideal for offhand shooting. If you also want to sometimes put it on the bench for more precision groups on paper you'll be able to hold center on the target just fine. It's not like being able to see the grain in paper or a piece of lint on the bullseye at 100yds is going to make much difference as I suggested earlier.
Happy optics hunting.
My AR22s are for offhand shooting only.
I use a 1x red dot on my 15-22 and 1-4x on my CMMG.
1-4x is just as good at 1x as the 1x red dot with the added benefit of magnification.
The 1x red dot is significantly lighter which is a plus for offhand shooting.