I did a search,
the use of the constriting band (cock ring) seems to be most important to those with undersized cylinders (ie, floppy glans). One person with that issue stated the following:
Floppy glans....problem solved
Postby Genome » Mon Nov 07, 2011 9:01 am
I am happy to report thay I have discovered a solution that satisfactorily addresses the issue of my floppy glans.  Many of you will remember that my doctor implanted me with an undersized Titan. This caused the end and head of my penis to flop around because i had a 6-inch implant in an 8+ inch dick. For a year I have been experimenting and discovered an old technology that came to my aid. A Cock Ring.
The implants destroy the ability of the top chambers (corpus cavernosum) to get an erection but the under-chamber (corpus spongiosum) and glans can inflate. By kegaling I can push blood into them which is trapped by the CR. If i wear a CR and stroke a bit, the spongiosum becomes partially erect and inflates the glans. This stabalizes the formerly floppy end of the shaft that was unsupported. My penis even gets veiny again with the cock ring. So I am rather pleased now and in no hurry to have another surgery....considering all the risks, discomfort and expense. It is not as good as a properly fitting implant....but it is very usable.
viewtopic.php?f=6&t=964There are others on that string that state that their doctors were not keen on the idea though