If you’re looking to map inputs from your controllers into MSFS 2020 or 24 that aren’t available natively in the simulator for mapping, you could also try Mobiflight. It’s simple to use and free to download, but if you use it regularly and like it then you can make a donation, or at least buy the developers a coffee now and again.
I don’t use spad.next, but then again I don’t have anything like a stream deck or other button panel that might need it. I have a VKB joystick & rudder pedals, stecs max throttle and their FSM-GA autopilot panel, a side extension module (VKB SEM) for ignition, start & various other controls and finally an additional throttle quad (the VKB THQ), with more buttons and axes for mixture & Prop.
All the axes, buttons, switches, toggles, levers, sliders and rotaries I have available to me can be mapped natively in either of the sims or via Mobiflight.
The reason I started to use it was because in 2020 the heading align function doesn’t work, and if you’re flying at low level on a bush trip or sightseeing this can be very useful. If you’re following a GPS line in NAV mode, but you need to navigate around e.g. a mountain or if you want to change course a bit to follow rivers, roads or railways, the heading align function moves the heading bug in the autopilot to match your current heading, so you can then switch to HDG mode and adjust your course with the HDG rotary without affecting anything else.
I’ve since found lots of extra controls that can’t be mapped in 2020 (or don’t work properly) which can be mapped via Mobiflight, so now I have VNAV and lots of other controls from the G1000 - map range, all the menu buttons and the FMS rotary knobs - mapped to my controllers so I don’t need to touch the mouse or keyboard any more in flight.
AIUI, spad.next offers a lot more options, compatibility and variability and it looks to be an amazing tool which is used and loved by lots of FS flyers, but if you don’t need all that functionality, then Mobiflight might be enough to accomplish what you need.
If you search the forum there are lots of other discussion threads on this kind of thing, but here’s an example: