Did you know, that Henry Ford already used a generator on the flywheel of his Model-T? No, the matching starter was only provided much later on. Nowadays, hand-cranking is of course, no longer necessary to start the engine. On the contrary, now one can take advantage of even the shortest breaks, to switch the engine off.
In the meantime, cars with stop-start-systems are considered to be micro-hybrids. This is because the cross-over is very smooth, hardly noticeable at all. Indeed, we're no longer speaking about a starter-motor with a sprocket gear, but a starter-generator, which is positioned around the flywheel.
Depending on the performance capabilities of the electric motor, the distance between the motor and the gearbox is somewhat larger. In a car with a front-mounted engine and rear-wheel drive this is probably not a problem, but also transverse engines, due to the greater track-width, the shorter gearbox, fewer cylinders and the shorter engine construction, have sufficient space (e.g., VR-engines).
The significant difference to the starter-motor with a sprocket gear, apart from the possible wear and tear, is that this, as a rule, can only start the engine. A starter-generator on the other hand, makes it possible to drive off directly. At which point the engine is actually started, is left to the controller. As you can see, in this case, a smooth, flowing cross-over to a fully fledged hybrid-drive is possible.
It all depends on the capacity of the installed battery. The starter-generator is capable of producing almost any voltage. It couldn't be more flexible. You may be ordering your next car with an almost infinitely variable price-list, which would depend on the possible range when using electricity alone. In addition, apart from the performance of the combustion engine, you may be able to choose the performance of the electric motor as well. 04/13