hey man, check out a custom jig called a "router planner sled" make that and use a router and no matter how uneven the boards are you can flatten the entire top then hit it with minimal sanding!
Instead of using pocket holes to attach the aprons to the top you can always use what are called figure 8’s. 20-Pack - Heavy Duty Figure 8 Table Top Connector or Desk Top Fastener Clip - 12 Gauge Steel www.amazon.com/dp/B06XZ6LV2Z/ref=cm_sw_r_cp_api_i_Z4aDEbG6X9DX1 Looking good!