So far I have not had good customer service. 

Basically, you ask permission from the mortgage servicer, who then informs the mortgage investor assuming they are good with it.

I hope you are asking two separate unrelated questions, because there's no point in doing cost segregation for properties held inside your self-directed solo 401k, save for some very rare exceptions.Some of the Bigger Pockets experts who operate reputable costs segregation companies are @Bernard Reisz, @Yonah Weiss and @Julio GonzalezSome of the Bigger Pockets experts who offer Solo 401k administrator services are @Dmitriy Fomichenko, again @Bernard Reisz and @Brian EastmanReach out to them and see if they can help.

We don't allow any "deal-making" in the forums, which includes advertising your services or properties, looking for partners, etc.

Personally, I enjoy self-managing and screening is my favorite thing, so I'm not in the market for PM services, but a lot of my clients that I work with and other fellow investors would be interested in it.

If my labor is worth $100 on Friday, I want it to buy the same amount of goods and services on Monday morning.  

Their customer service is great.

Pure client service.  

You pay the contractor for their services and then keep all of the profits. 

Securities and Investment Advisory Services offered through DFPG Investments, LLC.[1] Multnomah County Executive Rule No. 388, March 11, 2020[2]Marcus & Millichap, 2020 Multifamily North American Investment Forecast