Perfectly doable, I ran a Yamaha YZF-R125 for a few years, first year put 14k of mileage on, no problems, no discomfort. Did the restricted test, as it meant I didn’t need to hire a bike or tuition, straight passes on both parts of the test, then waited the two years till the restriction lifted. But new licence rules are in place, so depending on your age, you might need to take another test later. Loved my 125, enjoyed my ZX6R for a while, then it became dull, as after a few track days you realise you really can’t open the taps as hard as you like on the road and either keep a clean licence or live long.
PS If anyone want’s a bike, 2008 ZX6R £3k and it’s yours 😉