It WILL NOT be fine on the standard bolts.
The hub flange and bolt interface is only 6 threads wide, and there are no "spare" threads on the bolt.
6 threads is 10mm.
With a 5mm spacer, you've reduced thread engagement to 3 threads, which is ****ing dangerous.
Longer bolts must be used with ANY wheel spacer. If you dont, and you're lucky, you'll simply strip the threads when torquing them. If your unlucky, you'll strip the threads at 80mph and kill someone.
I would also personally only recommend using hubcentric spacers, and this means a minimum of 10mm. Thinner spacers often mean the spigot centering ring on the wheel is not engaged with the hub any more, which can cause vibrations and increases bolt loading even further.