Congrats in recognizing the value of skidpad time. And yes - its usually only available in very small amounts at HPDEs.
One thing that I did to get a lot of skidpad time was to attend a commercial HPDE that had skidpad offered. Commercial HPDEs (if they offer skidpad at all) usually have it an an option for participants - and very, very few people seem to be interested in it - so you can get a LOT of skidpad time because no-one is waiting.
Hope this helps.