Very good points. Thank you. The slick action on the VSR types is pretty much the only advantage that I see in them. The awkward action on the SRS is the only disadvantage. I've seen videos of them in use and people seem to get the hang of it although some people did make it look very awkward. I was surprised that the push bolt version was so badly received as it seems like a much more natural action. Obviously not.
I can't find anyone with the Rapax springs in stock but they're on the upgrade list as well as a few other tips I've seen to make the action smoother.
Scope alignment will have to be very much trial and improvement. Until I can shoulder one with my complete head-pro (helmet, goggles, mask, ear defenders) it's impossible to know. I can only hope the scope doesn't end up looking ridiculous.? I was wondering if the rail on the Sport can be extended? I've already got a cantilever mount so it's a good start.
I think that statement is pretty disengenuous personally, lest our bias sway the conversation away from where it is. The difference in cost isn't insignificant, and if you know what you're doing (or at the very least know which resources are, and are not trustworthy) a VSR can keep up with an SRS for much cheaper. Again, not to say you shouldn't go with the RIF you actually want... but I wouldn't worry about trying to justify it by boiling it down to statements about advantages and disadvantages.
They both absolutely have a place, the only thing an SRS can do which a VSR can't is be
THAT quiet (without HPA'ing/CO2'ing anyway), VSRs can be made very quiet but I'm yet to hear one that's as quiet as an SRS. Though there is absolutely an arguement to be made that given MEDs you don't actually 'need' a RIF to be as quiet as the SRS can be.
That aside, I'm sure you could cowboy/bodge the top rail longer if you absolutely wanted to but a cantilever should be more than enough. If you're planning on running it with a helmet and ear pro I suspect you're going to wind up with that scope being on stilts, but as you say, that'll be trial and error. My post was largely there as a 'this is something you should be aware of' rather than a 'this is a definitive fix for a common problem'... if that makes any sense at all!
Other thing to add to the pile of things to consider is parts availability, SRS parts can be a bit of nightmare to get your hands on. I can't speak from experience but I imagine that's only become worse since Brexit/COVID. That's not to say you
need a boat load of tat to throw in/on it, but I know you mentioned liking that side of things in your initial post so felt worth mentioning. (More than happy to be corrected on this if stock level issues have changed in the last 6 months). While on the subject of teching, neither RIF is particularly hard to tech on but the SRS is significantly easier to fine tune simply by the nature of how quick it is to tear down. That's not to say I think it's actually easier to work on versus a VSR, it's just more... convenient.
FWIW having had both my personal preference lands with the VSR, but that's largely down to how much I use the RIF. I feel much less guilty leaving the VSR in the case to use other RIFs than I did the SRS. I think the SRS is a great option for folks that are all in on 'sniping', but as a RIF for when you want to dabble the VSR is just a better fit.