Accelerating training is to increase skill proficiency. Members who have learned skills will lose their proficiency if they transfer to other means of transportation, unless they are retrained to 100% with gold coins, 80% are free, and 90% are silver coins, but their proficiency remains unchanged. However, if your 100% members don't learn skills, the experience gained by continuing to fight is still with them, but you just can't see it. If you click on the skill, you will find that the skill proficiency will be much better. If you don't learn skills, but transfer to another car for retraining, you will find that your proficiency is not the default 90%, but more, which is the intangible experience that plays a role.