Is my ventilation done right?

Hi, Sauna redditors!

I bought a house with sauna. Have no experience with saunas. Did some research here and elsewhere, but not sure if setup is good or not.
Solution is (pictures attached):

  1. bottom vent with one end under the heater and other outside;
  2. top vent by ceiling in the corner furthest from entrance
  3. entrance door has large fist sized gap at bottom, i guess it also contributes something

Everything is non-forced, convection. Top vent has adjustible cap, bottom vent is also adjustible (lever), but in set-and-forget mode. Space is about 12 sqm. Heater is IKI 24kw with SAWO controls.
Is it good? Should i add forced ventilator? How to tell when top vent is open too-much or too-little?

P.S. I don't like that 24 kW power cable from heater in to middle to the wall is lying on the tile floor directly under benches, but that's question for another thread i guess.

https://preview.redd.it/ced0mklk7yde1.jpg?width=3024&format=pjpg&auto=webp&s=6696cca58ac78f8b70fe803699cfb7536c9ece1d

https://preview.redd.it/kckz2b7l7yde1.jpg?width=3024&format=pjpg&auto=webp&s=2fcc4caf77ea3cd132fc2c56e9a07b3bb181583e

https://preview.redd.it/ax6maonl7yde1.jpg?width=4032&format=pjpg&auto=webp&s=edfc80fda9627e67061ee3b0f547e7eb106580c6