Hi @Alex-Kushleyev , @QSL 170-250mm is quite long. I'm not optimistic 250mm can even work, 170 would be risky.
We can offer our design services, but typically what that results in is a MOQ of a specific new item, such as 300-500pcs depending on the complexity (at normal MRSP which for flexes runs ~$50-80 each) and lead times would be ~14-18 weeks.
What we would need is a .dxf outline of your intended design and we can review that for feasibility and interest. If it really is 250mm, I'd prefer to no-bid it. 200mm might be the edge here (we do not have sophisticated Sigrity tools to confirm, so going on experience here).
M0170 is not ideally suited for back-to-back (the connectors are a bit offset from each other so the net result would be weird) but it may prove if 140mm can work + ~10 mm for the connector transition losses.
In situations like this, I encourage the ME/Industrial Design Team to reconsider placement of sensors and main electronics relative to each other. There are just some constraints the electronics cannot meet easily. Sometimes just simply re-prioritizing the system constraints helps solve the spatial/distance problems. To extend past ~180+mm, I would encourage you use an external design firm that knows how to do mipi repeaters and high speed design. We've had one customer successfully do that, but it takes some skill and we could do it ourselves, but we just do not have the design cycles to support it this calendar year.
Hope this helps and let us know what your thoughts are, and if pursuing us for a custom design is an option, we can reach out over email.