So asking people you know who can say something about your integrity, knowledge, & other characteristics that they like about you.

When they are being picky, it is just to protect the integrity of their paper trail for the regular custodial compliance audits they undergo. 

The downside is that it doesn't integrate with some website platforms.

My intention is to treat people with integrity and honor.

On one hand I am an ethical person so I feel that if they ask me to I should do just that for the integrity of my business, however, I have a sales background so I know persistence is key.

(I have no idea how to actually make this link correctly), my feelings weren't hurt, but I am big on integrity and it did feel like a set up to question my integrity.  

You claim to do business with Integrity and Transparency.

As is the case with any professional service, the quality of their work is directly tied to their experience and integrity, so selecting a qualified engineer plays a big part in the validity of the findings presented and used in the report they produce.Many Cost Segregation companies offer a "benchmark" study free of charge which will provide a conservative estimate of how much accelerated depreciation will come from segregating depreciable assets.

As for Property Managers - the quality and integrity varies a lot, but we help our clients connect with reputable PMs.

Any such system would compromise the structural integrity as you alluded to.