That breakfast sounds great, I can see why you do not want to miss it! Using Uber/Lyft should definitely help.
Going directly to BW from Pop may make it easier. Disney will hold your luggage at Pop if you want. Just head to Bell Services and they will give you a ticket. Bell Services will even keep something refrigerated say if you had medication or something perishable. Disney will also internally transfer your luggage to another resort if you go to Bell Services. I have had them do it and I think they say it could take up to 4 hours to arrive at the new resort. The Poly room may not be ready until 3pm anyway.
If you gave Bell Services at Pop all of your checked/large bags to transfer internally, went to BW via Uber/Lyft and had one bag with essentials/swim gear for Poly, finished breakfast, took another Uber/Lyft to Poly and relaxed at the pool for your room to be ready/luggage to arrive that may be more relaxing