I just prefer the variable size of reticles that FFP affords instead of SFP. I don't know if there are 'Rimfire specific' scopes with adj Para and prob FFP is rare also. I have a B22 with Covenant-4 6-24x50 FFP, and also on my CZ455 SS Lux. The 6x is OK for closer shots but the 24x is good at 100yds with FFP giving accurate holds. My Marlin 60 has a Tasco Sportsman Plus 4-12x40 with SF, Not specific 'rimfire' OR FFP but is quite light and 4x is fine for close-up. I have to 'pay attention' if changing distances as the reticle is 'fixed'. One of my Sav-64s has a 'Texas Weaver D4' that's as old-school as it gets and is fine for close also, but @ 50yds is only good for 1-2" groups.
All of this is just my preferences, YMMV.
PS - I forgot to add My CZ457 V-MTR has an Athlon Argos 8-34x56 FFP-SF and the whole rig weighs 12+ #. There is a couple FFP Athlon Talos models that prob will fit the $5-600 price, depending on the dealer - http s://athlonoptics.com/product-category/rifle-scopes/athlon-optics-rifle-scopes-talos-btr/
Again, not 'rimfire specific' and weighs 24-oz but also is Illuminated-Reticle.