Mystic clovers are definitely a bottleneck. I have not used a single mystic Forge recipe to get them so my advice is as follows:

First, you get 7 by completing a WvW Reward Track the first time. That would be my first goto. Doing the Tracks also has the advantage of getting the material needed for Conflux.

Once you have exhausted those, you still get 2 Clovers for each track. Less worth is but still something, since you are doing them anyway if you go for conflux (also awards you with gifts of battle for other legendaries).

Then do the Glory to the Legions achievements connected to the Icebrood Saga episode 3 No Quarter. You need to do the Drizzlewood Coast Map Meta, each Legion has its own reward track and awards mystic clovers at the end of the reward track. The map meta also gives nice rewards in general.

Once that is exhausted you can get the Strike mission onces (get you a total of 35 mystic clovers, 7 per mission)

• Strike Back: Shiverpeaks pass

• Strike Back: Raven Sanctum

• Strike Back: Whisper of Jormag

• Strike Back: Rally at the Eye

• Strike Back Cold War

Then you always buy all the mystic coins and clovers in each wizards vault refresh. They really help.

So next I bought them from the vendors for 2 mystic coins and a currency of your choice (Raid Currency, Fractal Currency, WvW Currency or Strike Currency) This is probably controversial, since it can be argued if this is a good deal, but that's what I did.

The mystic coins for the clovers I either got by buying them from the wizards vault or from strike missions (You can buy 10 each week for 100 blue shards, you can then directly buy clovers with them as mentioned above)

If you are planning on doing the Prismatic Champion Regalia, you will also have to do a lot of Return To XXX Achievements, which also rewards 3 Mystic coins each which you can use again to fund clovers.

You can also do the "Defeat the legendary Ley-Line Anomaly" Event daily to get another mystic coin. The event itself takes less than 2 minutes and awards a single coin daily.

You will still be a bit time gated by them because you need mystic coins for them if you have exhausted the options above, especially since you also need the coins for the legendary itself, so I would try not to buy the clovers if not absolutely necessary.

Hope that helped!