You're mashing with 4.5gal or 18 qts so that's about 1.6 qts/lb for your 11.35 lbs grain so you're close to your 1.5 estimate. Working backwards from your 5 gal bottling volume, add 0.5 bottling loss = 5.5 gal batch size + 0.25 trub loss + 0.24 cooling shrinkage = ~5.98 post boil volume needed + 1.13 gal boil off = 7.11 pre boil volume needed. My assumption on cooling loss and shrinkage is that is the expected decrease in volume of your liquid from boiling to fully cooled temperature (thermal contraction as it cools)
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