Hi Zappacat,
Well indeed as a temporary solution this might just work, as far as I can see from a quick look at the 305 from Behringer it should have some basic VCA functionality as well.
The main concern I have with this module is that it is 24 HP wide... in such a small rack as yours, are you sure you want to spend so much HP for a temporarily solution?
If a dual VCA would be temporarily sufficient enough for you, why you don't consider the Doepfer - A-130-2, that's a dual VCA (lin or exp) and is only 4 HP wide instead of 24 HP ! And it's cheaper than the Behringer but of course only two channels instead of 4 channels for the large 305.
Or the Doepfer A-138n is a basic 4 channel mixer, much cheaper and also 4 HP only.
Up to you of course, good luck with the decision :-) Kind regards, Garfield.
P.S.: Providing a link to your rack, as you did here is perfectly fine, one can click on it and then the current rack view will be visible. The good point of doing it like this is that a reviewer can then easily see the modules you have in your rack. With a picture that's not possible.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads