Does the prayer of one who joins it late become void if he stands up during or before the Imam's Tasleem, according to the Hanafis who consider Tasleem to be a Sunnah?

According to the Hanafis, saying the taslim (salutation) is obligatory. If a worshipper intentionally omits it, he is deemed to have acted wrongly, but his prayer is not invalidated. If he omits it out of forgetfulness, he should perform the prostration of forgetfulness (sujud al-sahw). A latecomer (masbuq) acts wrongly if he stands up to make up what he missed before the imam's taslim or during it, intentionally, but his prayer is not invalidated. If he does so out of forgetfulness, he should perform the prostration of forgetfulness.