I don’t know about NY but as per the ATF, a non functional brace can not be counted in measuring overall length.

From atf guidance letter

Consistent with the stated intent of the inventors, and as supported by the objective design features, FTISB has previously determined that “stabilizing braces” may be assembled on firearms as accessories designed to assist with the operation and use of certain pistols or firearms by aiding the shooter in stabilizing the firearm when firing. In contrast to stocks on rifles or shotguns however, such “stabilizing braces” are merely accessories and are not relevant to classification of a “pistol” under the statutory definition. That is, a folding stock on a rifle or shotgun is included in overall length measurement because the firearm must be “designed or redesigned, made or remade and intended to be fired from the shoulder” to be so classified. The stock is therefore an essential element in the statutory definition. Conversely, it is inappropriate to include a folding “stabilizing brace” accessory in the overall length measurement of a firearm because, unlike a rifle or shotgun, a stabilizing brace is not an element of either a statutory or regulatory definition of any firearm. Therefore, when a device operating as a stabilizing brace is attached to a firearm via a folding mechanism, overall length is measured with the brace in the folded position.