For deep rabbets on jobs that I didn't bring my CMS, I have on occasion clamped the pieces to the side of my MFT-3, leveled with the top and used a guiderail to make a cut in the narrow side. The cut in the wide side can usually be made with a guiderail on top of the MFT if you stuff up the back of the rail for narrower pieces.You'll probably have to clean up the cut, because the depth setting on the TS55 is only per mm , and the bottom of the kerf isn't flat.
I always carry a couple of chisels in my tooltote so cleaning up isn't that big a problem even if my OF 1010 is not with me on the job, and this method has worked for me on a couple of jobs.
Once I did a rabbet in a piece that was about twice as long as my MFT, so I had to cut the narrow side, and then loosen and reclamp it for the second half of the cut but if you mark your piece right, that won't be a problem.
It is however a lot easier if the part is shorter then the MFT, so you can use the grooves to house the clamps. The maximum rabbet depth using a TS55 on the guiderail is about 50mm, and on the MFT-3 you can use the full depth without "undercutting" the clamps.
If you have another bench with a flat top and a straight edge and possibility to clamp the piece to the side, you can of course use that instead of an MFT.
Regards,
Job