So this exists. 3 infinite combos in standard is kinda ridiculous. Whats more ridiculous is this tech list. All 3 combos that I know in the same list and optimized with the control and draw cards to get those combos faster. The side board includes more cards for clear depending on what you play against. Feedback are welcomed. Wanna optimize the deck before I bring it to FMN :)
Combo:
Saheeli Rai + Felidar Guardian. Infinite Felidar tokens with haste.
Wandering Fumarole + Crackdown Construct. Infinity/Infinity power and toughness Crackdown Construct.
1 Panharmonicon + 2 Decoction Module + Whirler Virtuoso. Infinite 1/1 Thopper flying tokens.
Tips:
Saheeli Rai + Felidar Guardian can end your opp one shot one turn 6. Try to bait out any counters and spells beforehand or try to wait for your opp to spend all their mana. Summon Felidar Guardian and blink 1 land back, then play Saheeli Rai with the last 3 land and finish the combo.
In the sideboard you will find slip thru space. If your opp is play too many creatures and you are not to worried about spells or counters, play slip thru space to get Crackdown Construct's damage in.
If early on you cannot play any of the combos, consider playing as many tokens or copies of any combos that you have to drag on the late game. Eventually you will have a Wandering Fumarole and/or the copies of Panharmonicon and Decoction Modules on the battlefield. Any draws into a Crackdown Construct or a Whirler Virtuoso would mean a instant win.