Aims : Flip-flops are top-hat-like X-ray flux variations which have been observed in some transient accreting black hole binary systems , and feature simultaneous changes in the spectral hardness and the Power Density Spectrum ( PDS ) .
They occur at a crucial time in the evolution of these systems , when the accretion disk emission starts to dominate over coronal emission .
Flip-flops remain a poorly understood phenomenon , so we aim to thoroughly investigate them in a system featuring several such transitions .

Methods : Within the multitude of observations of Swift J1658.2-4242 during its outburst in early 2018 , we detected 15 flip-flops , enabling a detailed analysis of their individual properties , and the differences between them .
We present observations by XMM-Newton , NuSTAR , Astrosat , Swift , Insight -HXMT , INTEGRAL , and ATCA .
We analyse their light curves , search for periodicities , compute their PDS , and fit their X-ray spectra , to investigate the source behaviour during flip-flop transitions , and how the interval featuring flip-flops differs from the rest of the outburst .

Results : The flip-flops of Swift J1658.2-4242 are of an extreme variety , exhibiting flux differences of up to 77 % within \sim 100 ~ { } \mathrm { s } , much larger than has been seen previously .
We observed radical changes in the PDS simultaneous with the sharp flux variations , featuring transitions between the Quasi-Periodic Oscillation types C and A , which have never been observed before .
Changes to the PDS are delayed , but more rapid than changes in the light curve .
Flip-flops occur in two intervals within the outburst , separated by about two weeks in which these phenomena were not seen .
Transitions between the two flip-flop states occurred at random integer multiples of a fundamental period , of 2.761 ~ { } \mathrm { ks } in the first interval , and 2.61 ~ { } \mathrm { ks } in the second .
Spectral analysis reveals the high and low flux flip-flop states to be very similar , but distinct from intervals lacking flip-flops .
A change in the inner temperature of the accretion disk is responsible for most of the flux difference in the flip-flops .
We also highlight the importance of correcting for the influence of the dust scattering halo on the X-ray spectra .