Rectilinear creates unappealing discoloration on the surface of the parts.
Prusaslicer has monotonic ironing, I have no idea why BL removed it. BL obviously sees that it makes a difference, because it’s the default for top and bottom surfaces. Please put it back, ironing is imo unusable.
Are you sure they removed it? Maybe it was just added after they forked it.
Can you point to any documentation for that? As I am not seeing mention of being able to configure the ironing pattern, but rather the top layer pattern when they talk about ironing…
And then, there is still an open issue on the PrusaSlicer GitHub requesting that concentric ironing be added… 
I don’t know where this suggesstion stands, but I would like to give it a bump. I would like to see this feature added as well. Cura had it when I used Creality printers and I got cleaner results on my Enders with ironing than I do on my P1S. 