Peter Dohm wrote:

...

Now, if we can just get rid of those damanble dolly launches to transfer the
amphibians from airport to seaplane base--and the belly landings coming
back...


They're working on it.

Meanwhile your options include repostionable floats (leaving the
gear fixed) and motorgliders, which are allowed retracts. Actually,
I haven't found a prohibition against multiple engines for
motorgliders either.

--

FF