With my previous RV,a Class A, I made wood ramps like these
I found that they were heavy and very hard to store.
With I bought my Class C I tried the Lego type blocks but found that they broke to easy and were a pain to setup when you don't get it right the first time and had to drive off,re-stack, and make them higher,to labor intensive.
When I bought my RV,
a Former Rental, it came with Tri Level Ramps They don't break and if they are good enough to withstand the use in that market they must be good,they still put them in their rentals
I have used them a lot in the last 10 years and have had no problems and they are easy to use and store. I have 6 just in case but never have used them all,4 is the most I have ever needed,most times just 2 if at all,they were for the rear duallys.
I found that
The Tri leveler work very well.
2006 TIOGA 26Q CHEVY 6.0 WORKHORSE VORTECFormer El Monte RV RentalRetired Teamster Local 692Buying A Rental Class C