I can't speak for AC but i doubt they would make a new backplate at this time with the 4000 series on the horizon.
Only the first versions of the 3090 benefitted greatly from an active backplate, having memory chips on both sides. Most new GPUs now have memory only on one side, using higher density memory chips. If yours is like that, you could stick to a traditional waterblock.
Or use the competitor's option... i have one besides me and that fat copper sandwitch just looks sick i have to admit
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