All experiments were performed on a Waters SELECT Series Cyclic IMS (Q-IM-TOF) with a commercially available, stainless steel, thin SID device (3-mm along the ion path) located after the selection quadrupole in place of the DRE lens prior to the Trap stacked ring ion guide used for CID. The instrument was operated in ion mobility mode, with ion mobility separation traveling wave (TW) static height of 25 V and TW velocity of 375 m/s. All instrument settings were tuned to be as gentle as possible to minimize protein complex restructuring, unless collision-induced structural changes were intended. In that case, the cone voltage was adjusted in 10 V steps from 0 -160 V to vary the amount of isCA (named "cone isCA" by Waters for consistency with older instruments, although the voltage variation does not involve a source cone). Subsequently, data were acquired without further activation (cone isCA), or with additional, intentional activation by another method (cone isCAfixed SID or cone isCA -ECD). Data acquired via cone isCA were collected in triplicate on three separate days. Data processing was accomplished using CIUSuite 2. Cone isCA -fixed SID experiments were performed at a fixed SID potential, for the indicated quadrupole-selected charge states, while scanning the cone voltage in 10 V steps. All data were obtained in triplicate. Final plots are the subsequent averages and error bars represent one standard deviation from the mean. For SA 11+ and CRP 17+, the SID potential was 45 V (495 and 765 eV, respectively). For PhosB 21+ the SID potential was 190 V (3990 eV). For TRAP the SID potential was 70 V for the 15+ charge state (1050 eV) and 50 V for the 21+ charge state (1050 eV). SID data for SA, CRP, and TRAP were processed using DriftScope v3.0 to extract oligomer intensities to be sum normalized and plotted as a function of cone voltage. The same procedure was followed to obtain weighted average SID monomer charge plots. When the SID data for PhosB were visualized in DriftScope, the precursor dimer and product monomer lines overlapped in a way that prevented signal intensity extraction. Thus, an alternative strategy was devised. First, Waters Raw files were converted to mzML files using ProteoWizard MSconvert 44 (version 3.0.23244-bc8a3ad) with the Scan Summing filter applied with the following parameters: Precursor tolerance ±0.05 m/z, Scan time tolerance ±5 s, ion mobility tolerance ±5 ms, and Sum MS1 scans. The mzML files were then imported to an HDF file and deconvolved using MetaUniDec, with the cone voltage as the input variable. MetaUniDec was then used to extract signal intensities and charge states for PhosB's monomer and dimer at each cone voltage.