Making the fastest PC alive. an update

so the question of how to make insanely fast characters has come up alot on this sub. but im dedicated to building the ultimate speedster and i've got an updated build with all the uncertain rulings, UA bullshit, and dm fiat i could find, as follows.

monk 2, wizard 2, artificer 1, barbarian 5, rogue 3, fighter 2, druid 4, mystic 1 tabaxi

wild shape to riding horse for 60ft

circle of dreams die +20ft

horseshoes of speed +30ft

monk gives +10ft unarmored movement

barbarian +10ft fast movement

elk totem +15ft

bladesong +10ft

swift step draught +20ft

mobile feat +10ft

longstrider +10ft

transmuters stone +10ft

boon of speed +30ft

celerity discipline +10ft

all together a base speed of 245ft

then use haste, potion of speed, boots of speed, and tabaxi racial ability which may or may not be allowed to work together for an X16 multiplier.

hasted speed 3920ft

now for actions. though action surge's bonus is in question

normal movement, dash action, dash bonus action, haste spell dash, spd.potion dash, action surge dash, action surge bonus dash

adding up to 27440ft per turn plus 1960 from rogue scouts reaction dash for 29400ft or 3340MPH or mach 4.66

EDIT: made the race tabaxi

EDIT2: dropped 2 levels of monk for 2 levels of bladesinger wizard, gave barb elk totem

EDIT3: added horseshoes of speed

EDIT5: added circle of dreams for druid lvls

EDIT6: dropped 1 wizard level changed to artificer added mystic for celerity

EDIT7: dropped ranger and some monk levels added rogue and druid levels for scout reaction dash and dream die