I know the maximum incline you would want to use in HO is 4%. I'm doing an inner and outer loop 4 x 8 layout and to plan for future expansion, I will put switches at all 4 corners of the table to get to and from possible future tables. I would like the inner loop to pass under the outer loop at both far ends of the current 4 x 8. My question is, what is the minimum height the outer loop has to be in order to get that done and can I get to that height at the start of an 18r curve by the far corner of the table ? Any thoughts ?