Due to serious influx of people trying to obtain accounts it has become very difficult (near impossible is some cases) to open as a tourist without a longterm visa.
The easiest path is through an agent at this time.
Volunteer Visas as a whole are nearly impossible to get now.
The exception seems to be in the religious sector as it seems to be business as usual.
Only very established and vetted volunteer programs are being successful.
The "I Volunteer in Chonburi and live in Phuket" Visa are done (for now anyway).
Dependant visas in these situations are extremely difficult or even impossible for some.
As to other Visas w/ agents, there is currently a slow down on the ability to get things done.
IF an applicant qualifies without any "fixing" needed , there is no problem to obtain a visa or extension by an agent or by simply doing it themselves.