GS to Contractor: Jerked around by all of these security offices?

My experience with clearances has been directly with agencies. Forgive my ignorance:

I’ve had an S on and off, multiple investigations but sequentially. Recently I’ve applied to contractors (USAJOBS is a nightmare), and I’m unfamiliar with their methods. All contractors are different but my confusion is the separate security teams’ guidance.

My hiring contractor, where I applied for a TS job and have been meeting investigators for over a year, is now pushing me into an Public Trust job with a small agency (I assume to get butts in seats).

The issue is this Public Trust agency is trying to start a brand new investigation with fingerprints and a new eQIP while the recent TS contract is ongoing. The secondary agency security office says the Trust can take half a year (the contractor security office said at most a month because my interim would seamlessly get me into the office: preliminary processing has already been a month). A higher interim clearance from a large department not transferring to a small agency is also new to me, but is probably common.

The contractor advised that OPM/DISCO wouldn’t know about the competing investigations until the TS is finished then inactive; I’ve read here though that two simultaneous investigations aren’t possible and are only effective when you have your first day at work anyway (but that “hiding” the position change is something companies informally do to open more contracts).

I’m worried bothering with with the earlier Public Trust opportunity is jeopardizing the time spent on the desirable TS job I originally accepted.

Can I really have two investigations by OPM/DISCO at the same time through eQIP without the feds recognizing (and thus cancelling one of them, probably the desirable TS I’ve been holding out on)? Shouldn’t an ongoing TS and interim S (and inactive full S within a decade) be sufficient for most of a Public Trust without a new eQIP? Is my interim S something I can carry with me outside this contractor? How can I best “preserve” the TS investigation progress, or am I in a tough spot?

Thanks Clearance Jobs!

I’m not an FSO. But I don’t think you can have two investigations at the same time.
One has to be concluded first. Besides “Public Trust” quiet frankly don’t open many doors.
If I were you I would call OPM to clarify this issue.