Just saw this old thread, want to comment for the benefit of other members because I use a Rondinax sometimes and the previous post may be misleading.
Normally you do *not* fill a Rondinax, it uses just 200 cc of solution, which gives a liquid level just below the axis of the spool. The film in the spool is kept wet by rotation, so you have to rotate the spool continuosly, which is good exercise for the hand. If you do not rotate the spool, the upper part of the spool loses solution because it flows down.
The rotation movement is similar to the way you would wind an old clock, turn a bit, stop a bit, turn again. But do not stop for more than a few seconds.
I have never tried to see what happens if you do not rotate continuously, but my guess is that you may get uneven development.
As for development time with continuous rotation, reduce by about 15% as compared to the classic procedure (1 minute initial agitation, then 1 inversion each minute). Most manufacturers will give recommended times for continuous agitation in their film data sheets: use them, or compare with other agitation methods given and do your own estimate.
The Rondinax system works perfectly with 36-exposure-rolls with the standard manufacturer's procedure. I am talking from actual experience with quite a few rolls.
If you do want to cover the spool with solution so you do not have to agitate so much, you would have to fill the tank until the liquid level is seen in the outlet pool. This might not be a good idea IMHO, as the liquid may easily flow over to the area where the cassette is loaded and you may be in for a full disassembly and cleaning after each roll, not to mention a soaked film cassette.