Liversidge, on 2019-December-30, 09:51, said:
Neil Rosen was written about this in the EBU's bridge magazine. He advocates the 100% GF version but acknowledges the drawback you mention - he says "As a result we often have quite a tough choice as to what to bid with various invitational hands, sometimes having to guess to bid no trumps without a full stopper".
"without full stopper" indeed! how about with 432?
On the left is is CyberYeti's problem hand for South.
If 4th-suit is G/F, then, over 2♣, South has a hard rebid problem
Admittedly, 2N is an awkward kludge, without a ♥ stop.
Unfortunately, however, bidding isn't an exact science,
Although, luckily, sometimes, 3N is a playable contract.