Recommended closed backs as they generally have more bass emphasis and bass reverb due to the closed design. Open headphones are generally will not give you as much bass quantity as closed headphones. The LCD-X has really nice bass for an open-back, so if you are unhappy with that, I don't think pursuing more open headphones would be the right move.
So deep bass would refer to bass-extension. Planars generally have good linear deep bass extension. That does not equate to bass emphasis/boost. In my own personal opinion, the LCD-X has among the best bass quality out of all the planars with a hefty amount of impact/slam/weight while keeping the bass notes relatively tight and it has great linear deep bass extension (a characteristic of most planar magnetic headphones). Bass is relatively balanced with the reset of the sound signature and that is a good thing. I don't think another pair of headphones will give you that sort of linear deep sub-bass extension with a good overall frequency response balance.
It sounded from your previous post you wanted more amount of bass. Usually, that equates a mid-bass boost in the FR (and that how I interpreted your statement as you enjoyed the MDR-1Rs which have a mid-bass boost). For open options with more of a mid-bass emphasis, perhaps consider looking into the Sennheiser HD650, HE-400 (headphones slightly on the heavier side), Beyerdynamic DT990, or Phillips X1 (not the X2 as it is tuned more neutral). Do note that most open backs won't have the same amount of bass quantity as closed headphones. If you really want open, I think the X1 or DT990 may be most suitable for your criteria. Otherwise, I think it may be wiser to go with a nice open-sounding closed headphone with a solid amount of bass boost, aka the TH900. I think the TH900 would fit your sound signature preferences the best if you can afford it. They are very open sounding for a pair of closed headphones and don't really noise isolate very well. Basically, considered semi-open (imo).