Hay cubes are the only true substitute for the “long-stem roughage” that hay provides. They do require a bit of planning ahead, as they need to soak. You can hurry the process with HOT water, but just be sure to cool the ENTIRE slop down before feeding. Stick your hand in there and mix it up good to eliminate the “hot spots”.
I have had Seniors that have flourished on just TC Sr, and did not ever receive soaked cubes for whatever reason, so roughage doesn’t have to be a necessity in every case.
I am not a fan of hay stretcher. I never have been. To me, it is glorified floor sweepings that just provides junk nutrition. It baffles me how it deserves the name “hay stretcher”.
Any bagged hay substance is going to be more expensive than the baled variety. I try to justify it by considering the fact that my seniors no longer consume baled hay, so that helps the budget. And, my old guys have served me, or someone else, for DECADES and they deserve to be taken care of until their time comes… My oldies are 43, 26, 23, and 23 right now.