I am in west part of Houston however my fill water is just at 200 TA - not over 300 as you have given for north Houston. As mentioned above by
@YippeeSkippy you will need to add the MA to drop TA and then aerate to increase pH. Do you have a separate water feature with its own pump? I have a waterfall that draws pool water from the side in the shallow end. Once my water is above that suction point I can turn on my waterfall to create a lot of aeration to raise pH while the main pool circulation is off. Maybe you have a similar setup or can configure your valves to flow a water feature (if you have one) to create aeration while you fill. If not, put on any type of water feature you may have once the pool is full. Having initially high TA is not the worst thing and it can be brought down in time. You will need to watch this as you add water during the hot months. Also, be mindful of your CYA and CL levels after your fill is done.
If you are really worried about it, you can put a sump pump in the pool and then have the return be a fountain back into the pool. This type of aeration may be beneficial. Hope this provides you some ideas.