I am setting up a large marklin digital layout and will be using multiple 66361 transformers to provide power to separate loops that will be connected via switch tracks so that engines can move from one loop to another. I know that blocks must be installed on the center rail so that one power supply does not come in contact with another. If my MS2 is connected to 1 of the transformers, will I still be able to control the engine when it crosses a block onto track powered by another of the transformers?

Hello Mike,
Good to see that you are setting up a layout again.

I believe that each time that you digital loco moves from one block to another block, you must un-plug your MS2 from the transformer where it was operating, and walk with it to the new block to plug it into the transformer there. You will have to do this each time your loco moves to a new block. That's the only way in which you will be able to operate your trains throughout all blocks on the layout.

Regards
John

Do not ask serious questions on April 1st.

Do not connect the MS2 to a transformer. Connect the MS2 to a trackbox and connect the trackbox to a transformer or a power supply.

Do not buy excessive power supplies when you only need additional feeder tracks.
If you need more power than a single trackbox can supply, consider adding boosters to your layout.

Transformers won't do any good on their own.
Transformers with additional trackboxes will make life complicated. OK, life is always complicated.
Transformers with boosters but without trackboxes will provide more power while things remain rather simple.

This will not work with mfx.
mfx always makes things complicated. Simplify your life and disable mfx - with MM or DCC things will work as described.

Sorry I wasnt clear. I know I need a track box between the power supply and the ms2. There is no way to connect the ms2 directly to a power supply that I am aware of. Again, I will need additional power, not feeder tracks since I'll be running up to 10 engines simultaneously. If I add boosters, I'll still need to add blocks to separate the power supplies, correct? And once an engine crosses a block, will 1 ms2 still be in control of the engine? I guess I'm asking how a digital engine gets its instructions from the ms2? Is it through the center rail, outside rails, or wirelessly?

Yes, today is April 1st, 2019!
The day of Nonsense!

If you say so.

Today is April 2nd. And mfx is still disabled in my Central Station. Disabling mfx solves many issues that are caused by mfx.
I never heard about a large layout with more than one controller (Tischbahning, Teppichbahning, ...) that used mfx. That would be nonsense.