I do not use the Rigol as a LA, but if your interest is in SPI decoding, Dave's video "MSO5000 Bug Bonanza" showed specific bugs related to the simplest SPI decoding, unfortunately there was no follow-up videos as to the current state. You need to check this before buying.
I don't know if that was ever fixed in the current firmware, perhaps other users can chime in.
My feeling is Rigol has decent hardware, but firmware support responsiveness is definitely ranked in the lower tier of the B-Brands (based specifically on my experience with the MSO5000 in the last year). So while the Rigol has potential for more sophisticated uses, if your use case is as you described, Keysight is by far the better supported brand of the two, especially when it comes to post-sale services.
I would agree with Gandalf_Sr, the LA probe in the Rigol is overpriced relative to what you get. You should definitely look into alternatives if you decided to go with the Rigol.