The 4GB exe I found in this guide. I don't know if it was patched specifically for DXVK or not, but I recall reading that it's just the exe from GOG.
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I tried running the game with the following
1. Monkey Patch + vanilla exe
2. Monkey Patch + DXVK, with the vanilla exe
3. Monkey Patch + 4GB exe, no DXVK
And in each case the framerate was still lower. Regarding the command line, that also doesn't seem to work. The sr2patch.txt that Monkey Patch generates indicates that the command was run as well, which is strange. Only the full Monkey Patch .dll seems to result in the lower framerate.