Bike fit / correct riding position

130mm stem on an already long race bike is pretty long

The Tarmac has a short wheelbase and came with a 90mm stem. I definitely feel the need to be more stretched out on it.
I was also told that you don't want to be able to see your front hub over the bars, but not sure if that relates to road bikes or not, and if there's any truth in that. The front hub was visible by some distance.
I don't think I'd go any longer than a 130mm.

I'm sure all the slammed stemmed "pros" out there will love it, as it's leaned against a cafe wall, never being ridden for more than an hour.

Goooood, this is what I'm after when I use it to cycle to Waitrose.

I am slightly regretting not buying the 58cm when I got it a 3/4 years ago, but I went off of what my other bikes are, which at the time were around 56cm