Release 3.4.0 -- the full quality range, and two more colour modes Qualities 0 through 31, the whole range the format can express. The field is a UINT8 but 31 is the highest value that means anything: the reference clamps any higher request to 31. Reaching it needed a change of method rather than more brute force. A deep coefficient's magnitude is bounded by the SAMPLE range, so 31-bit samples survive a shift near 30 where 8-bit samples survive 8: quality 28 is measured on a 64 KiB probe, where the old approach of doubling the image per quality would have needed 330 TiB for 31. Qualities 29 to 31 also required emulating a defect in the reference, deliberately. It computes its deadzone threshold in 32-bit signed arithmetic, which overflows at a divisor of 2^29 and wraps negative, switching the deadzone off. This encoder reproduces that, because the alternative is writing files the reference disagrees with; it is commented as a defect rather than a rule, and pinned by a test. Two more colour modes: modes 5 and 6 as 'untransformed5' and 'untransformed6' -- reconstruction measured, identity deliberately not asserted, since the two are byte-identical to each other and to already-named paths. Sixteen colour models over twenty measured (bpp, channels, mode) triples. Two overflow fixes, both latent behind bounds that hid them: the pyramid-depth clamp's shift was masked to five bits, so 32 levels wrote 32 on an image supporting 9; and the quantizer's divisor went negative at shift 31. The encoder's level bound now matches the decoder's, so it can write the depths the reference chooses. kMax leaves the undetermined list by being shown impossible rather than measured. The reserved header bytes are characterised as an encoder constant, ignored on read. 595 tests. Conformance unchanged where already established.