  Unfortunately, yes, it is. In ref.[1] it has been shown that without fixing
the reaction-amplitude phase, many combinations of partial waves at neighboring
energies in single-energy, single-channel partial wave analysis reproduce
experimental data identically, but are discontinuous and disconnected. To
obtain the continuous solution, the phase has to be fixed to some continuous
value. In the same reference it has also been shown that the change of angular
part of reaction-amplitude phase mixes partial waves, so the pole structure of
any single-energy single-channel partial wave analysis depends on the chosen
phase. As in any single-channel analysis the overall reaction-amplitude phase
cannot be determined because of continuum ambiguity, it is in principle free
and has to be taken from some coupled-channel model. Because of the difference
in the angular part of the phase, choosing different phases results in the
change of the pole content of the obtained solution. Therefore, single-energy
single-channel partial wave analysis is inherently model dependent, and the
number of poles it contains strongly depends on the choice of the phase. In
that reference these facts have been illustrated on the pseudo-scalar meson
production toy model. This truth is now for the measured observables
demonstrated on the realistic model of ref. [2] which combines amplitude and
partial wave analysis in one self-consistent scheme for the the world
collection of {\eta}-photoproduction data, and fixes the phase to BG2014-2
solution [3]. We show that the pole structure of the solution whose phase is
very close to the BG2014-2 theoretical ED phase is very similar to the pole
structure of BG2014-2 solution, but the agreement with the data is not ideal.
However, improving the agreement with the data requires the departure from
BG2014-2 ED phase, and this spoils analytic structure of the obtained solution.
