Safe/easy way to elevate tracked cat for maintainence?

A RR tie under each track works great. If you can find a couple nicer, fairly square ones is even better.

Any decent pieces of timber will be fine , just don't use concrete brick etc ...

One each RR tie per side is what I use. Problem is in Ca. they have been banned due to creosote so they can be hard to find.

I dug a slot in the ground about 12 inches deep---made the walls out of 2 rr ties each on top of each other--inside ID equaled the id of my 4U tracks--long enough to reach belly pan from rear---slight slope to slot draining out the open end so need ground that is on slight slope to build it
can't find the pic right now

You can also just pick up a couple of 4x4s or 6x6s from Home Depot. They don't have to be railroad ties. If you pick up a few, you can build a custom height and width. If you have a slope, you can dig them into the slope so you can drive on level. If you get really fancy, you can use some 6x6s as piles and basically make an open air pit you can stand under

The benefit of RR ties is they are treated to reduce rot.
If your going to use anything else make sure it is pressure treated lumber.

One each RR tie per side is what I use. Problem is in Ca. they have been banned due to creosote so they can be hard to find.

that is amazing OM almost unbelievable to me but I have heard some amazing things about California
And yet we can by it over the counter out here still from most hardware shops

Creosoted timber was banned 2 years ago in New York State---so was CCA treated timber so they now use CZA treatment---but none nowhere as good as the creosote