The preparatory period for party membership is almost over, but I don’t want to become a full member at this time.

Step back from the brink. If you don't want to become a regular member, it means that the party organization will make a decision to cancel the qualifications as a probationary party member, and this decision will be included in your file. If you go into a private company or work alone after graduation, that's fine. If you go into a government institution or a state-owned enterprise, they will review your files, and your heavy-handed brushstrokes will make everything go wrong for you.