How can I make the processing time for I-829 for my EB-5 direct investment faster?

You will still be a permanent resident while waiting. If too much time has passed after filing (like 18-24 months) without a decision, you may be able to file a writ of mandamus to compel the USCIS to decide.

You may only apply 90 days before the conditional residence expires. No way to make it faster, barring life-and-death reason.

I-829 processing times are three to four-and-a-half years. Estimated time range from the USCIS website is: 35.5 months to 55 months.

Currently, it is about 35.5 to 55 months. Sorry, but no real way to expedite it. After you file do not forget to get your annual I-551 stamp to ensure you have proof of legal residency.

These cases are taking up to 30 months. Consider filing a mandamus.

You must submit the I-829 petition within 90 days, not 120 days, prior to the end of your conditional residence status. If you file too early, the USCIS will reject/return your I-829 petition. Once you timely file your I-829 petition, the USCIS will mail you a receipt notice extending your conditional residence for 18 months, work and travel authorized. Other than falling into one of USCIS'' very specific expedite criteria, see https://www.uscis.gov/forms/filing-guidance/how-to-make-an-expedite-request, there is no way to speed up the USCIS processing of your I-829 petition unless you file a mandamus lawsuit for unreasonable delay. Even that probably should not be tried until your I-829 petition has been pending for a couple of years.

Normal processing time is anywhere from two-and-a-half years to four years. Of course, the time can become slightly quicker or slightly longer depending on when you exactly apply.

You cannot file earlier than 90 days before expiration. There is little you can do to speed it up other than doing a great job with the application and supporting evidence.