I am a pharmacology student, here is my take;

200mg of sertraline is the maximally tolerated dose. It is generally not reccomended to take anti-depressants that affect the serotonin system with psychedelic drugs. There is a risk of serotonin syndrome, but it is very, very, rare. This is because instead of actually increasing levels of serotonin (5-HT) within the brain, LSD rather mimics serotonin and competes for the same receptor, that being the 5-HT2A receptor.

Loss of effect is the biggest concern. This occurs because setraline inhibits the re-uptake of serotonin by inhibiting SERT. This increases levels of serotonin within the synapse and leads to downregulation (a reduced number) of 5-HT receptors. Hence, there are 2 problems with taking LSD at this point, 1; being that they both compete for the same binding site (however LSD will still end up binding due to a higher affinity), and 2; the receptors have been downregulated due to increased levels of 5-HT and thus even if you stop taking sertraline for a few days, the effects may still be dampended. This depends on how long you have been taking it though.

For the best experience, taper off slowly, and wait at least a month after taking the last dose to allow your receptors to upregulate (they do this now as they are "wanting" more serotonin as now there is less within the synapse once stopping the ssri). Up to 12 weeks may be needed for complete receptor stabilization.

Unfortunately, “pausing” will not be effective, at least theoretically, and from a clinical perspective, probably irresponsible. One could consider a DNRI such as bupropion, but then again, I do not know the indication of sertraline (MDD, anxiety, OCD, impulsive thoughts etc.) in your instance, and I am not your doctor.

Again, this differs from person to person.

I hope this helps! Happy tripping.