Seeking help with a pressure tower – pressure control scheme for the tower top?

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As shown in the figure, it is a butane stripping tower with pressure control at the top of the tower. I found information online; there are 3 different methods for controlling the pressure at the top of a pressurized tower: ① When the condenser at the top of the tower is a fractional condenser, the tower pressure is generally adjusted based on the amount of vapor taken out. Under constant other conditions, an increase in the amount of vapor taken out leads to a decrease in pressure； The gas-phase recovery rate decreases and the pressure rises. 　②When the top condenser is a total condenser, the column pressure is usually adjusted by the amount of refrigerant used, which is equivalent to adjusting the reflux flow. 　③Thermal bypass (immersed) method is used to regulate tower pressure (as shown in Figure 6-4). Regarding the pressure control method at the top of the tower shown in the diagram, it seems that two or three different approaches have been combined into a single proportional control scheme; I’m not sure whether this will work or not Furthermore, in the case of a thermal bypass control scheme, the condenser requires a certain liquid level; therefore, its position must be lower than that of the liquid level in the return tank. Additionally, the outlet pipe of the condenser needs to be inserted into the liquid phase of the return tank. With this control method, is it necessary to place the condenser below the return tank when arranging the equipment?