TPS is backup and has nothing to do with h1b stamping...moreover you are not doing cos from TPS to h1b...I don't think your TPS will be impacted but during re registration ( if extended) of TPS they may issue RFE asking why you were out of country as one of the general req of TPS is continuous stay in US.. Call USCIS .. There is an option which you direct you to people who can answer TPS related questions ....