True, but i'd immagine that arranging a system with both superchargers on fluid couplings might be a mit complex, probalby more than necessary. Adding a second stage with 1 or 2 speeds would have been practical and if only used at high alt in addition to the fluid coupled stage the stepped power changes would not be nearly as drastic as contemproaries. (though with the added compression of air, and the resulting air tep increase, an intercooler may be necessary)
And the location of the second stage is something else to consider, the German engines (Jumo 210/11/13 and 600/01/05/03 had sid mounted superchargers with the added bonus of facilitating a "motor cannon." Though 2-stages were possible as shown with the 213E/F, and an intercooler was used on the higher altitude E version, but omited on the F which was tuned for the med alt range)
But on the single stage itsself the limitations are mainly of compression ratio and mass flow, both effected by rpm limits, hence a arger compressor could adress this as well, without the added stage. Though there is a limit to a centrifugal compressor's compression abilities, in the case of the operating circumstances this doesn't go much over 2:1, though some could get closer to 3:1 but those levels are inefficient for this use and would sap a lot of power, a turbo may be more reasonable with them though.
Those used on the early jets though can manage 2.8 at the lower end (the HeS-3b managed this, the HeS-8 about 2.9) and the Welland 3.5, Derwent I 4.0, Derwent V 4.3, J31 4.5, some Nene's and J48's 5.5:1.
But again jut mentioning it for curiosity, as those kind of values are not practical for a supercharger. And for al practical purposes a second stage is needed to acheive higher pressures at reasonable efficiency.