Another Chromacor question

This is another one for the experts.

I've read here that for an achromat doublet the recommended f ratio is 3*D minimum, and preferably 5*D. I think the Chromacor was designed to work with the Synta 6" f8 and 4.7" f8.3 scopes, but not the short tube f5 versions. These two expressed in the previous terms are 1.33*D and 1.77*D respectively. I've also read that the Chromacor was optimized to operate around f10.

The question is... Would a Chromacor work with a 4" f6 (i.e., 1.5*D), or would it be better suited to say a 4" f10 (Celestron C-102 with 2" focuser adaptation) or 5" f9 (Meade AR-5)?

The designer of the Chromacor, Valery Deryuzhin, regularly responds to posts inquiring about the Chromacor at the Yahoo Chinese Refractor group.

http://groups.yahoo.com/group/Chinese_Refractor/messages/

Just remembered, the Chromacor also corrects for spherical abberration. There are 5 different degrees of correction -2 degrees over, 2 degrees under and a null correction. By utilizing one of the various levels of correction, I think the Chromacor can be utilized for various F ratios. The below link to a page at apm-us shows test results of Chromacor with various F ration scopes.

http://www.apm-us.com/amateur/chromacorr.htm