General aviation pilot reported the Los Angeles TAC and VFR flyaway charts do not reflect the DSNEE6 Arrival path and could place VFR aircraft in direct conflict with aircraft on that arrival; especially VFR aircraft utilizing the practice area.

Narrative

This report involves loss of separation and charting errors. I was flying Aircraft X in Southern California as part of a mountain flying course. This course required practicing maneuvers at a normal maneuvering altitude (3;000 feet AGL) and at a high altitude (10;000 feet density altitude) in an area without mountainous terrain. The purpose of these low and high altitude maneuvers is to compare aircraft performance in a range of maneuvers at low and high altitudes before performing them near mountainous terrain.My instructor and I chose to do these maneuvers at the Lake Matthews practice area near Corona; CA. This practice area is charted on the Los Angeles TAC chart as an INTENSIVE FLIGHT TRAINING" area; and gives an air-to-air frequency below 4;500 feet. In this area; the TAC chart shows an IFR arrival route between 8;000 to 10;000 feet along V283 and also on the 185 radial of Paradise VOR (PDZ) to KAYOH. The VFR flyway chart shows the same IFR arrival routes. This corresponds with the KAYOH8 Arrival into SNA and LGB. These routes are south and west of the practice area; respectively. Given this information; we planned to complete the flight north of V283 and east of the PDZ 185 radial. However; the primary arrival for SNA from the east is the DSNEE6 Arrival. This arrival is not displayed as an IFR arrival route on the TAC or VFR flyway chart. The DSNEE6 Arrival directs airplanes to be at exactly 8;000 feet over the DSNEE intersection. The DSNEE intersection is 1 nautical mile south of the Lake Matthews visual waypoint; VPLLM. Thus; any aircraft operating in the Lake Matthews practice area at 8;000 feet will directly conflict with the uncharted DSNEE6 Arrival.I climbed to 9;500 feet MSL; which on this day was about 10;000 feet density altitude. I was using ADS-B; but I was not in contact with SoCal TRACON for flight following since we were climbing; descending; and constantly changing headings as part of the practice maneuvers. As we conducted our maneuvers; we noticed several jet aircraft descending in our vicinity. We maintained visual separation; but were confused as to why these aircraft were farther north and east of the charted arrival paths. After spotting two jet aircraft flying the same path; we contacted SoCal TRACON. SoCal informed us that we were interfering with the DSNEE6 Arrival path; and that one aircraft received a TCAS RA due to our position. SoCal then directed us to an area where we could complete the high-altitude maneuvers without conflicting with other traffic. They also gave us a phone number to call after the flight. When I called after the flight; the controller explained that while we were in Class E airspace; we were in an area of high traffic for jet arrivals into SNA and LGB. They explained the DSNEE6 Arrival goes right over Lake Matthews. I reported that the TAC and VFR flyway charts did not show any arrival paths in this area. The controller then gave some advice on low traffic areas where these maneuvers could be completed in the future.Given the events described above; it is imperative that FAA revise the Los Angeles TAC and VFR flyway charts to reflect the DSNEE6 Arrival path. Not only do the charts omit the DSNEE8 Arrival path - the flyway chart recommends flying on a path from Pleasants Peak; over Lake Matthews; to BNG at 7;500 feet. Flying eastbound on this path at 7;500 feet puts VFR aircraft in direct conflict with aircraft on the DSNEE6 Arrival that are descending to 8;000 feet at DSNEE and to 6;300 feet at BONVY. The BONVY intersection is directly on this recommended 7;500 feet VFR corridor. If a VFR aircraft follows this recommended route; that aircraft will likely cause a TCAS RA - or worse; a midair collision. FAA must act to avoid this preventable scenario."