Era B&W film in HC110. What starting time for N+1~ N+2

Hi !
I've shot some Era 4x5 sheet film, and I'm urged to process it, without having time to make a decent calibration.
As the subject was very flat, I'll need N+2 (but even N+1 could make my day).
I will use my normal processing regimen using HC110 at 1+63 dilution.
Any advice would be good and appreciated !
Have a nice day !

At that dilution it looks like you use hc110 as a compsating develper so I would start at your normal dev. time plus 30% to get to a D+1 and maybe 15 to 20% more if you want N+2. The shadows should be fully developed, and should not block up.